... it would be a terrible waste if this wasn't expanded to a double-page table, with entries for Expert, Master and Legendary skill uses too!
As is stands now, you spend a feat-equivalent to up a skill from, say, Trained to Expert. As it stands now, that all that this gets you is a +1 to your skill rolls. Even with the new step-10 system, this a bad feat in and of itself.
And the fact that new uses of skills are effectively gated behind those 'skill increase feats' effectively makes then: Feat taxes.
In my opinion, feat taxes are bad and ought to be avoided wherever possible.
Take for example the 'Kip Up' skill feat. You need to be a Master in acrobatics to get to stand up from prone without provoking, also you MUST do it as a Reaction.
But what if you'd rather keep your Reaction (because you are fighting with a shield maybe) and spend an action to get up, but would like to avoid an AoO? Even though not everyone even has AoOs?
Would it not be much better if, for example, an Expert can get up as a single action without provoking, or maybe a huge bonus to his AC, a Master can do it as a Reaction or without provoking, and a Legend can do what the feat promises as a matter of fact?
A feat worth taking would be something along the lines of 'Kip Up and Strike', you may take an action to get up and strike, but your attack counts as the second attack on your turn and takes a -5 to-hit penalty?
There is a lot of tweaking to do here, but the bottom line is: Getting a new level of skill mastery ought to open up new uses of the skill as a matter of fact, skill feats ought to build up on that, not lock things out so nobody can try them at all.