It would be cool to have two dimmer suns as well. With offset intervals. So you get a good deal of morning/evening light the majority of the time but then sometimes get dark and super bright. Multidirectional shadows 
Tbh I don’t think this is a sovereign world issue but a game wide graphical issue. The problem with trying to make weather effects work for everyone is the abundance of variance in hardware/software configurations amongst users. If they added an option to decrease and disable weather I think it would be a moot point.
I don’t see why not.
To be fair, you do have some input as to biome size weather you knew it or not. For example if a planet requires only 1 T4 biome and 5 T6 biomes but you select 10 T4 and 5 T6 you end up with large T5 biomes and small jumbled together T4 biomes.
If you keep the ratios similar like Luca suggested you should come out with a tiny biomes planet that are relatively consistent in size.