Do the m22 speakers attach to the ss16's or do they just rest on them?

As far as I know they just rest. Some people talk about using double-sided tape to hold 'em together but AFAIK most people just sit the speakers on the stands and don't worry about it...

Thats what I do. The M22's are heavy enough that they feel solid on stands.

its true that they feel fairly solid on the stands but you certainly wouldn't want any kids in the room !!