In particular the skill feats are woe-fully out of date. I think I've seen before a suggestion to scale the bonuses with level. Something like Level/4. That in itself is good but I'd go further.
Some small, mechanically easy (to implement) additions such as guard effects (low % perhaps also scaling), defensive buffs (+1 PRR/MRR/Fort) and even cosmetic affects would help to make these feats more palatable and help to make even more interesting and flexible builds (not that there aren't lots of these already!).
Here are a couple of examples;
Athletic
You enjoy early morning runs, cold showers and doing pull-ups in old barns. A trek across the Searing Heights with a fully loaded pack is an easy day hike for you.
+2 Balance, +2 Swim, +1 PRR, +2% Fortification
or even better
+2 Balance, +2 Swim, +1 PRR, You stand up 25% faster when knocked prone
Negotiator
Hind legs and donkeys are forever mutually exclusive in your presence. Your bartering skills are legendary and market stall traders run in fear at the mention of your name.
+2 Diplomacy, +2 Haggle, Your 'Buy Back' is extended to 72 hours and your Auction House costs are reduced by 25%
I'd also love to see some more generalist/flavour feats and potentially racial feats although I appreciate enhancement trees fulfil these requirements somewhat and this is more work. 5e has some good examples - Magic Initiate, Armour Mastery and Increased Speed (Mobility in 5e) could all be fun.