Yiannis is correct for 2.5 durability balls @ 120, I think I've read 2.0 and less have about 90-100.
Putts from green are excluded, putts from fringe count. Mulligans count 2 hits (the original hit plus the mulligan) from anywhere, even on the green.
I've also read on here (not sure if its been confirmed) that "Gimme's" and "Conceded" putts also take a stroke off your ball, which makes no sense since putts from the green don't take any. If that's the case, you would be better off at the start of a MP or Alt Shot round to inform your playing partners you'd just prefer to putt everything out.