yip depending on finish etc normally use a 60grit pad (80's + get clogged up too quickly as its too fine a grit))
Only if I need to, I try to get it as smooth as possible without the need for buffing. Admitted its not always achievable
always more peace of mind more than anything, with a water base you shouldnt need to but I prefer giving it abit of a key before I prime/glue anyway, and all day long on a cheap 2 part as you can be the best screeder going but you will always get a couple of bits your not happy with when your using the budget gear.
It does what it says on the tin (or bag). It does flow lovely, it's like NA or 1200. Next day, however, is like you've landed on the moon with all the craters and dust.
Just use the new Screedmaster Flow from Bostik, you wont need to buff it off as it gives you the perfect finish.