I agree with (1) and (3) wholeheartedly. It was annoying trying to get what characters I could so I could assemble the perfect 3-man team (with Serge in the lead as always) with so many people to choose from. The accents kept me from being able to fully understand what the hell they were saying, though often times it wasn't hard.
For (2) I would propose even the NPCs from CT (Gina, Gaspar, Melchior, King Guardia, Fritz, etc.) would appear, not just those from the Seven (Crono [YES, TEAFLOWER VAGRANT, CRONO] and the rest).
On a personal note, they should give Miguel a happy ending. He can show up on Opassa Beach, having found himself at the entrance to the Sea of Eden in 1010 AD with his memories (of his imprisonment and the encounter with Serge at Nadia's Bell) still there, and has lived his life in Arni ever since.
EDIT: Whoops, wrong person. My bad, teaflower.