I like the idea, but I'd prefer to have flame on RE's instead of a separate flame rifle unit. I think that would make it more consistent with the other flame infantry. Rifle company can have M18's to replace that slot
Recoilless Rifles were basically portable direct-fire artillery, I think the idea of essentially an AI Bazooka is a bit too strong. It doesn't fit in CoH2 any more than units automatically throwing Grenades do, and I think even those could work under the right circumstances (RE Fighting Position).