make a mallet yourself or buy one from a fellow player. those eighth inch ones are too expensive and really are heavy, plus the diy aspect of polo is something that should be preserved.
rules vary from place to place. most places are stoked to see someone interested and are willing to answer whatever questions you have.
as far as fixed/free debate, its really what you are more comfortable with. there are benefits and drawbacks to both. also applies to front or rear brake. and the size of tires, and mountainbike vs road/track/fixie stlyle bikes. pretty much, if you keep coming back, you will figure out what works best for yourself. don't take anyones word as gospel, because nothing is set in stone.