we run a nippendenso alternator in our kit. so the one andy has in his kit should work. there are a few variations of the nippendenso alternator but we have adapters for most if needed.

on the ac the 508 will circulate all the refrigerant, it just might take a little longer than the RV2 and by that I mean its going to 30 seconds to a minute longer at idle. obviously cool down will take as long as it does based on how much flow you have going through the condenser in front of the radiator.

I don't think running it all the time will be a problem. these are meant to run in production cars. there probably is some peak duty cycle you don't want to exceed but don't forget these are used on minivans these days that have rear seat ac as well and they work just fine there.