Look at 1:58 for the snap roll in the Hayabusa. It's possible to do this in Il-2, but it's not as sharp. It's hard to time the exit (I end the roll about half a turn too early or too late) and the plane wallows around a bit and ends in a nose down attitude. It looks very sloppy overall, but it can be done.
I've attempted it a few times and maybe I'll post the track later. Considering our hardware, I would still say that this isn't bad.
Regarding stalls, you have to ignore the little blue HUD message. It does not indicate a stall, but a deep stall or spin. I have done proper power-on, power-off stalls in Il-2 without the "Stall!" message appearing.
But considering how much the IL-2 FM changed since its inception, I would not be worried about CoD too much. I think the team has enough on its plate already to worry about fixing FMs for now.