I just want to point something out that I thought would be obvious... but apparently it is not after having read all 500+ posts on this thread.
They said "UNCHAINED", as in a departure from the shackles of one's current state.
Skill points, feats, initiative order, hit points, action types (free, swift, immediate, move, standard, full-round), armor class, and much more could all very well become a thing of the past.
After all, these things are all carry-over from the 3.X era. And my hope is that some of these new rules, optional or otherwise, will eradicate these sloppy concepts with well thought out new ideas to simplify not just combat but the entire game.
This is Paizo, they brought us the simpler system of Combat Maneuvers already. I expect brilliant new ideas going forward.
With the aforementioned information in mind... what I want to see is a skill test system for everything, most especially trap finding. Make trap finding something more than some one in the party spotting a trap and the rogue disabling it because he just happens to have +1 to +10 points better in disable from his class. Make it worthwhile to be a rogue! You remember that D&D movie that only the otaku/cult mentality types liked because they love D&D that much? I want to see traps like that! That's what makes it exciting to be a rogue. I want to be a rogue because the game makes it worthwhile and fun to be one, not because the party needs one "just in case we run into a trap".
Melee types like fighter and barbarian need a mechanic for making use of their high armor (or damage reduction) and hit points to force enemies in combat to focus on them. Give us a threat system, and give certain classes like rogues and rangers a way to ignore threat so that they can target that pesky spell user anyways.
You remember all of those books that were published for D&D worlds? Arcane and Divine spell casters need something like that. Where their whole task in combat is thwarting an identified enemy caster in order to protect their allies. Seriously, go read the Elminster series. He spends 75% of his career thwarting other casters just so his allies with swords and spears can do the real damage. Only 10% of his career is spent soloing high level devils in hell... and by that point he was level 25+ and had the favor of a goddess.
Above all, expand on your teamwork feats idea. GIVE US MORE BENEFITS FOR WORKING TOGETHER AS A TEAM AND LESS BENEFITS FOR BEING THE STRONGEST IN THE PARTY! It is a team game, not a soloist game. Reward the party with a system that supports teamwork. Butterfly's Sting was a step in the right direction. The bard with it could boost his ac with the combat expertise feat no one ever wants so he can stand toe to toe in melee, spend his move action to grant the party bonuses, and use his attacks to go for a critical strike which he could then let his much stronger barbarian friend with a scythe do the real damage by taking advantage of the exposed area the bard revealed with the sting feat! MORE OF THIS, MORE OF IT, MORE! We need more players working together to pull off amazing combinations like this and fewer players running characters like synthesist summoners who can do everything by themselves.
(Yes I have synthesist hate, and it comes from a place that it rips off the 3.X druid and does it 5x better)