Anything will fit with the slip on end pieces, but those end pieces do absolutely nothing, they don't even change the sound of the bike.
Yes. I've also got the grab rail attachment, as my wife prefers this to the Ducati handles. (Their now for sale when I get round to it lol)
You need to get your head around the slip ons, they take up no more room than the standard slip ons and are made by many manufacturers, and the full systems, Akros (high level) and Termis (low level). The Akros interfere with the panniers and the rear footrests, but the Termi does not. The full system also gets rid of the cat and the exhaust flapper valve.
I would rather go Termi full system. I'll see what dealer can do but if not, I'll sort it myself. As I will definitely want hard panniers, it will have to be low level. Not a big thing though as I am not against standard. I just think that the Temis look better. If I can lose the cat, then all good.