I had a much more elegant reply written earlier this afternoon; the website ate it. So, trying this again...
Feat bloat is a real problem, but it isn't as if the third party solution is avoiding rules bloat.
There's a difference between feat bloat and rules bloat. The latter is an instance of how many rules you need to know in order to play the game. Feat bloat, by contrast, carried with it an escalating opportunity cost, as there are more and more feats competing for the same few slots.
Likewise, the third-party option I outlined above actually does avoid rules bloat, because it hinges on removing the standard use of Knowledge (local) in favor of that variant. When you've subtracted one thing and replaced it with another, the overall net result is the same.
Basically you've added another skill to the system that has non-standard and unique mechanics. In this case, the mechanic is quite similar to having a skill which does nothing on its own but allows you to buy skill stunts. For the cost of 1 skill point, you get a skill stunt that lets you make skill checks in one of several other knowledge skills at a high chance of success, but only if they pertain to a particular location.
There are a number of things here that need to be cleared up. First is that this use of a skill is "non-standard and unique," that's not the case. Speak Language, in v.3.5, operates under a similar principle in that each skill point spent grants a unique result, rather than adding to a single escalating bonus.
Second, while I'm not sure what precisely you mean by "skill stunts," it's worthwhile to note that the actual use of Knowledge (local) checks, under this rule, are exactly the same as they normally would be. You still make a particular check at a particular DC when Knowledge (local) is called for.
Finally, there's nothing to suggest that you use this version of Knowledge (local) where any other skill would come into play. As noted above, it still covers the exact same niche, save for the fact that it's no longer universal in its applicability.
It's also worth noting that the "very high chance of success" is fairly relative. Skill bonuses are one of the easiest things to increase in d20 System-based games. It's easily conceivable that a character can hit a +15 bonus in a Knowledge skill well before their levels hit the double digits, for instance, which means that they'll eventually reach the same level of knowledge that they would under this variant, save that it'll apply to all localities everywhere.
The idea behind repurposing skill points being I suppose that PC's have more of them than they have feats. But in terms of the complexity of the game, the skill stunt solution is certainly more complicated than feat bloat. Just imagine even the bloat to the size of the stat block when someone invests 15 skill points in Knowledge Local stunts.
I imagine that "bloat" will be very little. There's not much different between a line that says "Knowledge (local) +5" and one that says "Knowledge (local; Evereska, Shadowdale, Tantras, Waterdeep) +16". It'd add a line, two at most; we're not talking about paragraphs - more importantly, it's not adding new mechanics that need to be memorized and taken into account throughout the rest of the stat block or, for that matter, encounter.
As far as blurring the lines between Knowledge (Local) and Gather Information, I don't see how that is possible under my solution since I've defined both out of existence (and did so like 10 years ago). There is no such thing as 'Knowledge (Local)' in my game. Any question you might ask about a location is covered by a different knowledge type, whether law, culture, persons, geography, history or whatever and you simply roll against that. Any social research you might want to perform of the 'Gather Information' sort is handled by a proposition communicating where you want to go and what you want to learn, and a social skill check depending on your methodology in wanting to learn it. Any academic research you'd want to perform (say in a library) is just essentially an assisted knowledge check of the appropriate sort. So there is no blurring of the lines at all.
Insofar as the mechanics go, I agree that they're not conflated if you make one a feat and the other a skill. But that's not what I was trying to convey (though I admittedly didn't make this clear enough). Rather, I was speaking to the idea of Gather Information and Knowledge (local) being concerned with the same thematic area, rather than similar-but-different areas, which is how I see them.
And yet, Knowledge (Local) doesn't feel jumbled to you? Gather Information doesn't feel jumbled to you?
Not particularly, no. It's worth noting that I'm using "jumbled" here to refer to several unrelated areas of task resolution being kludged under the same mechanics. Knowledge (local) and Gather Information both occupy distinctly different areas in my view, and deal with those areas and no others. The only instance of jumbling is having Knowledge (local) refer to both information about a place and having it define what you know about certain categories of monsters.
What I really want to avoid is the problem you see in GURPS where skills are so precisely defined and yet so ununiform in their granularity that they become nonsense, so that for each specific skill you must essentially define a half-dozen alternative skills that can accomplish the same task, but at different degrees of difficulty. So the problem with Gather Information, Profession, or Knowledge (Local) is that they don't see to define any area of knowledge exclusive to themselves.
I think that this speaks to a larger divide about how to approach skill checks. Some people prefer that each skill be distinct in what it can handle with no area of overlap, so that you can't use skill X to solve a problem that requires skill Y, even if they deal with related areas. Others prefer to look at skills with related areas as "different ways to solve the same problem," and allow for skills X, Y, and Z to be used (albeit sometimes with different DCs).
Moreover, the two aren't mutually exclusive, as I've seen examples where people move back and forth between the two ideas, depending on the circumstance.
There is no logical reason why someone with great oratorical skills and great knowledge of the law wouldn't perform well in the capacity of lawyer, and no reason why someone with profession (lawyer) should perform well in it unless they also have great oratorical skills and knowledge of the law. Likewise, there is no reason why someone skilled in making friends, in lying, and in intimidating people to get them to do what they want and knowledgable about the area should have difficulty gathering information and finding informants, and no reason to think that someone who isn't skilled in making friends, or in lying, or in intimidating people to do what they want and who lacks any knowledge of the area should be skilled in gathering information. You've defined more than one way to do things, which is 'skill bloat'.
Insofar as the terminology as concerned, I don't see expanded uses for the existing skills as "skill bloat" - that's a term that I'd use only for adding new skills to the game altogether. While I do think that allowing uses for skills to overlap with other skills is something best avoided, that's not an instance of bloat, to me - it's more of a dilution.
In many ways this is worse than 'feat bloat', as feat bloat is a problem mostly at 'compile time' where as skill bloat creates problems during 'run time' - that is, during play.
Here I disagree. The opportunity cost that comes with choosing feats means that a poor choice about feat selection can haunt you far worse than a poor choice for a few skill points. Skill bonuses occupy a fairly high range; having a bonus that's too high or too low is a relatively minor concern (in fact, a good or a poor d20 roll can bridge that concern entirely for a given check), and so there's little regret to be found in spending or not spending a skill point or two here or there.
Feats, by contrast, are not only far rarer - one slot every two or three levels, rather than a pool of points every level - but they're also more binary. Having a feat, as often as not, opens up a few possibility that you simply couldn't do before. For skills, that only goes for some skills, and only for the first point spent. Not having taken the right feat can follow you past leveling and into the course of the game fairly easily because of that.
The ad hoc wording of the 'Local' feat that I suggested wasn't in any way intended to be final or well thought out in every regard, but to cover the idea that I think 'Knowledge (Local)' or 'Gather Information' is trying to cover, which I think one of the 'Indiana Jones' skill sets - that of seeming to always have a contact everywhere and always seeming to understand the locality that he is in. Other systems try to handle this by enumerating contacts or by a special power that grants you a contact everywhere, but those systems are from my experience very klunky and unsatisfying as well. Indiana Jones presumably already has been everywhere, as a highly experienced adventurer by the time we see him, something not necessarily true of your average adventurer. Instead, I'm trying to attack the problem from the direction of having the natural talent to become something like Indiana Jones or any other character with that chamleon like ability to just fit in. And in the sense of 'fitting in', the feat in question was intended to broadly grant that ability. Linguistic ability, disguise, social skills, and gathering and knowing information all are part of that. It's no more jumbled than the idea of being an especially good sailor. And its far less jumbled than the notion of being something core to the D&D story like 'an especially good warrior' or 'an especially good wizard', which requires lots of bloat and detail. Whether or not it is 'worthwhile' to call on 'I'm good at fitting in' compared to 'I'm good at fighting', depends on what the experience of play at a particular table is.
I'm sympathetic to what you're trying to do here - I just think that the system if working against you. You're trying to input a level of variability that's non-class/level-based into a class/level-based system. It's not surprising that you went with feats to do that, as they're the primary place where the game rules allow for that level of variability to exist.
The consequence of that, however, is that feats have had to absorb that variability so totally that they're now oversaturated with it to a degree that's outstripped their capacity to handle, in terms of how prevalent they are in the process of character creation/representation. Feats are now not only competing with each other for a limited amount of feat slots, but also competing with each other for the degree of non-class-based representation you want to imbue into your character (actual role-playing notwithstanding).
If you want to take a feat that indicates you have contacts in every port, for example, you have to weigh that against needing to wait a few levels before you get to pick another feat (and so it better be useful for those levels), but also against the other feats that help to define your character, such as a feat that lets him tell lies so slick that even magic can miss them, or being able to disarm a character at range with his whip, etc.
I'm suggesting that skills, which are already viewed as having little comparative value compared to feats (and spells, magic items, etc.) have enough room to absorb some of that representative ability, and ease the burden on feats.
