I wouldn't worry too much about the rolling. DS has been rolling for 6 weeks now - but can't roll with a wrap on. I do wrap very tightly (and I actually use a sarong because he's a big boy) - so he can't kick his leg over /swing his arm over - which he needs to do to roll.

I have been wondering about when to stop - I am planning on a similar strategy to Snacks - Grobag + light wrapping until he gets used to no wrap.