Some offset don't fit as they catch the ball ends, it's my personal preference to use nothing below 3mm offset as then I know they will with no problems, 6mm offset are even better I've found through using a lot of different types of wheels over the years, I buy mine from China most of the time and just wait for them to be delivered the same as the tyres, they are cheap enough it's just the waiting for them to arrive that is the pain really.
Si.