Matt, no you cannot automatically instruct raa with a gr 2. You still need to convert the rating. If your hubby wants the airlines, he needs to get his but into gear and get those atpls.
I'll say it again, i am no raa basher, i'm all for it. I was a former raa cfi myself. I just think the standards set by the raa are not enforced enough. Like I said, I have seen some dodgy raa instructors in my time. I knew a cfi who, with a wink and nudge, used to hand out instructor ratings.
That aside, on the most part there are some excellent raa instructors out there. As for the op, go for it!