Post dust to get it softer?
Silks?
No brushing?
Depends, but most of the time yes if there isn't any damage to the rug.... Judgement calls when tumbling rugs with tassel loss, moth damage, stiff rugs, ect.... Believe it or not, I've seen 90line Chinese rugs have the tassels untwist after going in a tumbler.... Care should be kept in mind.... I rather be safe than sorry....
If you do a lot of silk rugs, get the silk brush from Paul Lucas of ChemMax... It's the one you put on the Certified Pile Lifter... Basically a circular carding brush.... Makes fast work of grooming silks...