I think you could be in for a lot of track trouble if you were to put that few studs in. The power output of the motor will overpower the gripping power of the studs, and that's where people start to get tear-outs and such. I know that the stud companies have guidelines tailored for the style of riding that a person would do. And I think that often you can use the 1 stud per HP to get a starting point. If it were mine, I definitely wouldn't do it with that few.
In my opinion, if you like to be loose and slide around, you shouldn't bother with studs at all. Personally, I love the grip that studs give you. We run 120 on our 500, and that thing hooks up like mad, both acceleration and stopping. That number is generally considered for 'aggressive' riding for that motor size. They were on the sled when we bought it used, so I have no way of knowing just how long they have been in use, but we have experienced NO track damage. I've got 144 on the 700, and that has been a good setup as well.
I have no opinions on the belt issue, I've only run the Polaris brand so far. Been thinking of maybe trying others if there is a significant cost savings, but have not needed to buy for a while, and don't plan on needing to this year either, unless something happens to fail. . . .
TomS.
Minneapolis, MN, USA
'98 Polaris XC 700
lotsa miles, a few bolt-ons ;)
'99 Polaris XC 500 SP
wife's sled