Isn't the scaling feats a little like what the Tome house rules are trying to do?
If so, I think I'm against this system.
Why?
Because tome has the idea of buffing all the classes, by making feats better, but mainly buffing the martial classes.
Now a lot of tier 3 and above classes already laugh when you come with "level appropriate" encounters. A level 12 wizard have little problems taking out anything that is level 12.
If you just buff the martial classes, you've just made the gap between player classes and monsters bigger. Or you need to re-write all monster entries.
A better solution would be to make the casters worse, instead of making the martials better. That would create an even ground with the monsters, making encounters more deadly.
The issue with 3.5 is IMO not that the fighter is to weak compared to monsters. But that the wizard is to strong compared to the monsters.
Make the fighter better and you just skew this more in favor of the Player Characters, which makes the game rather stupid IMO, making the DM have to use CR15 mobs to make the encounters fair, thereby messing up the experience system.