I have a reamer its handy but not necessary, if you have a drill press then you could drill the hole closer to the exact dia. of the engine shaft, using a regular drill is a crap shoot its really easy to oval out the hole and the prop is done.

I am not overly nutty about checking balance,some guys are real OCD about it, but after opening up the hole its a good idea to check the prop balance,the larger the prop the more it makes a difference, just to make sure its not way out of tru