Removing AC pump from a 360

1 AC and non AC use different alternator brackets, if you're going for a clean look, find a set of non AC alternator brackets

(On a side note, non AC alternators use a single belt, where AC alternators use 2 belts. You can run a single belt on your 2 belt pulley, but I don't like the look of it)

2 if you don't mind spending the money on a full set of pulleys, a serpentine belt setup MAY be easier to come by, but I don't think you NEED all new pulleys
In my opinion, in this case, a serpentine belt set up is a waste of funds

Remember, all you need to do is set the alternator in loose spot and run a string around the pulleys
Measure the string and ask for a belt in the same size at your local auto parts store

3 well, yes, but not really
With the AC compresser mounted, you are spinning its pulley
Technically, that takes power
In all honesty, you will see a bigger improvement by removing the weight of the compressor

I dont know if a serpentine belt would use less power then a V belt

4 see point 2 on how to figure out the belt you need
The real issue is finding the right brackets (and that can be achieved by posting a simple wanted add here)