Nice list. I would put Arles ahead of Avignon. Avignon was a bit 'grey hair brigade' and too touristy/false for my liking. Arles had a very nice vibe for a small town. Felt like the locals were real locals living real lives.
Aix en Provence I hated. Met some nice people there, but the centre was just way to far up it's own arse. Drive through and forget it
Marseille surprised (and shocked) me. I want to go back. It is a hard city mind. No soft glow tourism daydream!
Have fun. I'm sure you will love it. If it wasn't so expensive I'd be planning return visits soon.
Good travel advice as always Stanley. Cheers