I also use EA and ActiveSky (7877) but with ASCA (7668) instead of Volumetric Clouds (set to OFF) and get great results (visual clouds and sky effects) - but no FPS drops. Could you please check if you have also those problems with the other Aerosoft Airbus models or happens it with the A330 only?
I'm as frustrated as anyone, save maybe the people who directly work on this project, but the CRJ uses a different type of code than most add-on for Flight Simulator. The fixes that work for others likely do not apply here, and as a developer, the explanation seems credible when Aerosoft says that the underlying cause is something only Asobo can fix. I don't think this is a case of this simply not being a high priority to them.