Reducing the number of feats ...
Quote Buttercup, "Evidently I'm in a small minority that likes the +2 to two skills feats. [..] +4 yes, penalty for exceeding maximum rank, no. Some people really *are* remarkably skilled."
My aim was to remove the two skill affinity and Skill Focus feats and combine them into a single feat. I do agree that the reduction in bonus when exceeding maximum rank is mechanically unwieldy. That leaves us with this fix:
SKILL FOCUS:
Benefit - Get 4 points to apply as an untyped bonus to any of your skills. You may spend at most 4 such points on a single skill, and you may take this feat multiple times.
[Removing Weapon Finesse]
Quote Buttercup, "I disagree. I think taking it as a feat simulates the character having learned to do this."
I have a couple of issues with Weapon Finesse. Firstly, it has a BAB +1 requirement. Secondly, this results in many animals getting it as a bonus racial feat, because they can't otherwise take it.
Those problems aside, the question is: is a DEX-based fighter, who doesn't have to pay a feat for Weapon Finesse, better than a STR-based fighter? I think the answer is no. STR is better, because it increases damage, vs. DEX which increases AC - i.e. offense is better than defense usually. If you believe that a DEX-based fighter may be too good, then making them pay a feat is reasonable.
[Diehard: +3 HP and stabilize on -1 to -9 HP or keep operating]
Quote Buttercup, "I think every Wizard and Sorcerer would take this at first level. Therefore, it's probably too powerful. Now if it could not be taken unless the subject had a CON of 13+, or perhaps at higher than 1st level, I'd buy it."
It certainly is a feat worth taking if one has low CON. The question is whether it is better than other feats that one might take at 1st level. Keep in mind that it is a defensive feat, so it is somewhat limited in power. Compare it to Weapon Focus or Spell Focus, which increase offensive ability.
[Mobility: +4 AC, +2 to Tumble checks to avoid attacks of opportunity]
Quote drnuncheon, "Even then, this feat becomes useless once you get enough tumble to ignore AoOs even on a '1' - your addition just makes that happen two levels earlier. Perhaps a better solution is to use one of the Tumble variants that makes it an opposed roll vs. the opponent's attack roll. This doesn't necessitate any change to Mobility, since people will be more than happy to have that +4AC on the times when they fail..."
I have a high level Rogue-type character, with a Tumble score of 19 and skill mastery in Tumble. So DC 29 without any problems. The DC to tumble past someone is 15, but 25 if you want to do it at full speed. Thus it is very easy with terrain penalties or multiple opponents to not be able to do a full speed tumble ... i.e. increasing Tumble hasn't become useless yet, despite a high score.
I do have issues with skills affecting combat. One option would be to entirely remove Tumble affecting combat (combine the remaining skill ability with Balance), but to make Mobility a bonus feat for Rogue at an appropriate level - say at 6th level. I would also be tempted to increase the AC bonus on Mobility to +6.
In general, I agree with you. Mobility is a waste of a feat, if one can use Tumble. By the same token, if you use Tumble opposed by attack roll, then at high levels Tumble will be useless: high CR opponents have even higher attack bonus, as HD, BAB and STR all tend to scale faster than CR. It also complicates the mechanics, which is a good thing to avoid.
Quote Greylock,"[..] several of the feats you mention really aren't weak. The char I'm playing right now has, from your above list, Armor Proficiency Heavy (as yet unused), Dodge, Mobility, Exotic Weapon Proficiency, and Mounted Combat, among others."
Heavy Armor Proficiency is not weak. It gives you another +3 AC over Medium Armor Proficiency, if you have DEX 12 or lower.
Dodge is not that weak either, but it is a pain to remember the +1 AC bonus applies to only one opponent. It is much easier to factor it into your AC once, rather than for separate opponents. I do think that making it apply to all opponents increases its effectiveness, which helps bring it closer to par vs. Weapon Focus.
Mobility is okay, if you wear heavy armor and have low DEX. Otherwise, you should put some ranks into Tumble, and avoid wasting a feat. At high levels, this is even worthwhile if those ranks are cross-class - it's not like a Fighter has good skills to throw ranks at. This is a good reason for making Mobility a bit more useful for those who use Tumble, rather than just making it a crappy feat for a DEX-based combatant on the feat chain to Spring Attack.
Exotic Weapon Proficiency - again, it's okay, gives +1 damage ideally (e.g. Bastardsword vs. Longsword). The AU rules for heavy and light exotic weapons adds versatility, without making it otherwise more powerful. I think versatility is a good thing for flavor, especially with randomly generated treasure, which is why I would go with the AU rule.
Mounted Combat ... I've never seen a character make good use of these feats, and Sean Reynolds considers them weak, so I thought it was worth combining them. Sean's feat points are here (note I don't agree with all of his pricings, but they're a good point to start from when comparing the value of feats):
http://www.seankreynolds.com/rpgfiles/misc/featpointsystem.html