The revised action economy does a fairly good job of explaining things but one thing I can't really find an explanation for is Rapid Shot and Many Shot. Many shot only triggers on a full attack action and Rapid Shot gives you an extra attack at your full BAB at the cost of giving -2 to all your attacks.
The way I see Rapid Shot working is it just gives you an extra act (like haste but not stacking with haste) for a single attack but then I don't understand how the -2 on all attacks would work now. TWF only applies on the attack you choose to TWF to my understanding so I guess that extra act would be at a -2.
Many shot though is interesting because you need to make a full attack. Under the revised action economy I can't see how to make it work because if you only choose to make one attack and then do other stuff it shouldn't work.
In my games, I make it behave like Two-Weapon Fighting feats do. They simply give you extra attacks on later attack actions if you so choose (with -2 penalties, assuming the character chose to use them for the turn). Rapid Shot allows for 2 attacks on the 1st attack action, and Multi-shot for 2 attacks on the 2nd attack action (and if using the Stamina rules, it opens up a combat trick for the 3rd attack as well).
Archery is already a very powerful combat style in Natural Pathfinder. And generally Martials are buffed under Revised Action Economy, since everyone becomes much more mobile. Combining those two, a mobile archer makes for a very powerful character/opponent.
Thanks for the input, that's a good way to do it.