I assure you, a great many people do care about Golarion. Firechanter might not, but that's not a viable data point to make setting decisions around.
And this is straight-up false; the interplay between nations, powers, and of course divinities is a big part of what makes Golarion appealing. It's a setting that can accommodate intersectional adventurers just as readily as self-contained ones.
Uh... wouldn't that move them closer to 5e? Everything there is "per-rest."
I think P1 has enough patches, fixes and solid content that P2 could just be a streamlined version of that with the chaff cut out. Take a bunch of the clarifications they've provided in FAQ and books like Ultimate Intrigue/Campaign and make them baseline, along with a bunch of the stuff from Unchained. Design a great experience from levels 1-15 and then make everything past that be a glorious, partially-balanced mess the way it is now. Embrace being the rules-heavy, high-magic, yet still accessible and open-source Android alternative to 5th edition's iOS.