anything above like 5-8mm spacer and you'll need extended studs. at least going with a 25mm spacer it'll give you a bolt on solution and you'll be done. no need to do anything, not even trimming down the stock studs. and adding 25mm to the offset of the wheel is going to be the only way you'll get closer to a flush look. i'd honestly vote for a different set of wheels, but you don't want that.
no, it's just like running low offset wheels so long as everything is bolted on appropriately. everyone who says they are bad for bearings is terrible at physics.