Marty: thanks a lot for all the suggestions. As for Gratulin: it is such a small issue, I can probably live with it. I did for the past like... 6 months, and I had fun.
The only 3rd party apps I run that you don't are FFBClip and Wally's tyre engineer (but only recently). They are not up on the screen most of the time, they are both the newest ones, and they do not seem to make much difference anyway in terms of performance. The only app I noticed making a difference is ptracker. I don't know if it is the latest one as it is updated so often I lost it. It has been disabled in the past weeks, though, as after 1.5 it was giving me troubles a bit.
I need to use v-sync because otherwise I get some stuttering or some tearing (depending on the cap I use). In general I think I reached a very decent compromise, and I am a bit scared of changing anything