I think natives are best of the remaining. Their UB is relevant and it is the only of the 4 civs with fishing while the rest all have myst (meaning we are guaranteed to get one of them). They are a counter to both aztecs and to rome, while they do suck against war chariots, they are faster getting out than war chariots (being available with bronzeworking directly and not requiring resources), and as such can limit the ability of the egypt player to get horses.
With stonehenge and feudalism newly built / conquered cities can chop out 2 pop longbowmen before barracks (or CG3 if our NA ends up as protective). Henge gets better for the team who have Native america. It also allow us to build guerilla and woodie 2 archers which can be huge.
Taking NA prevents them from getting a resourceless counter to our impis (while jaguars are probably stronger than impi's they can't actually beat them if the impis are on defensive terrain, and with 2 movement they will almost always be on defensive terrain). I would much rather they have a resourceless counter to our chariots than to our impis. Also since they don't have mali, they will get a lot stronger defensive units midgame (due to the UB) then they otherwise would have if they get NA.
Main city raider: Plain cats and swordsmen (or agressive), if they aren't working any improved tiles while we are, they got a problem.
5th pick will be either maya, inca, india or korea (all civs with myst).
@ chopping and slaving quechas: I agree that slaving them can be problematic, but before math chopping them isn't any problem. If the game goes long enough they also give us the ability to amass happiness cheaply while still having access to metal everywhere. That said I now believe we shouldn't pick Incas as they are too easily countrable (aztec, but also native america and maya can easily counter them).