Thanks for the support, Pete. What I meant about the controls being too sensitive was that with a Boeing for ex, it rolls and pitches too violently with a small amount of yoke input, making it behavior like an acrobatic plane. I will check your suggestions.
As for the fog, I understood from the manual that FSUIPC can generate a fake fog layer:
On FS2004, the upper altitude of restricted visibility can be set by FSUIPC, for global and local weather injected by
external programs. This allows you to limit the thickness of the fog or mist layer so that when you climb out of it you get blue
skies (or fancy clouds) above and around you, but still see the mist below. It’s a really nice feature of FS2004.
Indeed AS has an option to add a cloud layer but it is not that good.