I'm flying the .46 size kit with TT 91 FS that weighs 7.5. I followed the recommended throws (updated throws that is.) I do have a lot of throw on full rates and let me tell you I left them on by accident while taking off and almost snapped it in to the ground on take off. Mine snaps (or rolls hard) to the left just like you describe on excessive throws. I fly mine sport and that is all. I think what you are experiencing is normal for this airplane.

My throws are set up as follows

Elevator duel rate: 5/16 (flies great)
Full rate: 3/4