If ever there was a track which suited the "slow-in, fast out" mantra, this is it. The hardest corner for me to get right was Lavant. The braking point is far sooner than you expect, and you need to be on the throttle at the point of the first apex otherwise you lose too much speed on the following straight.
@Mistah_MCA puts up superb lap guides on YouTube. Hope these help you shave a few tenths if you haven't checked them out already.
Also, as you mention in your post, your consistent lap times = good results, so well done. I'm definitely guilty of over-pushing and taking the odd excursion, so perhaps you're best served by ignoring my advice completely
FYI, I do have the same problem as you with the Ferrari. It feels ferociously fast to me, but I can't match my Lambo times.