Hiya.
So long as it is RAI and codified by the DM. I love rules interpretations and new ways of doing things but these are house rules, RAI is a little different.
I like to know up front if I make a character with a feat that it will do what it says. Not what the DM thinks it says, (or vice versus on that logic). There is a bit of rug getting pulled out from under you if a DM uses the intent of the designer to make rulings. You wanted to have light thrown weapons be used with power throw feat. You believe because it does not explicitly say that light weapons cannot be used that you should be able to power throw a dagger. The DM believes that Power Throw is like Power Attack and light weapons cannot be used because you have to have power attack to get power throw and this is what the designers intended. Stuff like that will come up and the player has to either say whatever, I can't use the feat with my daggers or ask to change the character's feat or whatever.
This is actually a good example of why I keep telling 3.x/PF/4e people to "stop thinking like a 3.x/PF/4e player". With the advent of 3e, we ended up with a system trying to, basically, have a "rule or category for everything". The (I assume) hope was that with more stuff covered, it would be easier for people to run a game. In stead, what ended up happening is that a whole new generation of RPG'ers were taught "if you can't find a rule in your books, you need to by more books". The idea that the DM would be able to "make it up" was anathema to how they saw the game. We would have players coming onto various forum and ask questions so basic, so simple, so...."common sensey'ish" that it could get to the point of insanity. Questions kinda like the one in your example.
If a rule doesn't say you
can't do something, then obviously you can?

So, I want to use my characters Rope Use skill to build a suit of full plate armor I can...because "the rule doesn't say I can't"? Does that make
any sense at all? Any? This is the heart of the RAW problem; you simply can not have a rule cover 'everything'. Impossible. You will
always need the DM to interpret how the rule is to be applied in unusual situations. Always. It's one of the major reason RPG's even have a DM. It is the ONE thing that makes them totally unique from other games like poker, chess, monopoly, etc.; that one person playing (DM) has the power to change rules of the game on the fly.
In the example of Power Throw...it's not the rules fault. I'd say that sits squarely on the players shoulders. Either the player just wasn't thinking along those lines at all, in which case he would likely be genuinely surprised by a DM ruling against it...or he was thinking about it and thought "
Ha! I'm so smart! I can totally screw the rules on this one! I found a loop-hole! I'm invincible!!", in which case said player needs a swift kick to the dice for being a d-bag. If he thought about it, paused, and thought "Hmmm. Seems kinda vague in this situation..."....he should have went to his DM for an interpretation.
That is, IMHO, why 5e is written the way it is. It's trying to go back to the way it's alway...er...it was (sorry, we still play 1e AD&D...so it's always been this way for me/us...). Where the players and the DM create their own campaign, with it's own quirks and foibles. I think the "vagueness" of some of the rules is specific to reinforce the role of the DM in the campaign...players will come across something that isn't clearly spelled out, or can be interpreted one of two or three ways. At that point, they have to go to their DM to point it out, and then the DM (usually with player input) make a ruling that makes sense to them. Chances are that the ruling won't be so far out of whack that someone from another game will have no clue what's going on if they join the group (at least, I've never encountered anything so vastly different with regards to 1e AD&D that I was left scratching my head....not that I can remember, anyway...).
Sorry for the longish post, but I needed to get that said. RAI are far superior to RAW. RAW are good as long as they are vague to begin with. You can have useful RAW that are vague...it's finding that fine line between "usefully" vague and "wtf?!?" vague.
^_^
Paul L. Ming