Totally don't expect it to go over well, actually. But Vienna is Vienna, just a bit pushy and such. ;) So yes, it could be really interesting. Awww! Poor guilty and traumatized David.
Definitely! Zach could use more friends, for sure.
I think if it were in Miah's character to get jealous he probably would. As it is he'll just be more confused than anything else....and probably struggle to figure out his 'place' in the new dynamic. And he may be a little bit like 'you should see the skeletons in my closet' - Ellie's about the ONLY person he's consistent and stable with.
Regan's friendly with everyone, so I don't see why not. Especially if David and Silas will be friends.