Correct. Which also makes statistical sense... There are only 40 ways of making a natural straight flush, but over 2500 ways to make a wild one.
According to the rules we were playing, yes. (and again, this makes sense mathematically if you are going to make a distinction between natural and wild hands. There are 624 ways to make natural quads, but over 30k wild).
Obviously that's not the rule in all wild card games, but it was in the game we were playing.
As it happened we had multiple cases of wild straight flushes and wild quads over wild quads but no natural quads or straight flushes all night.