In terms of bigger-name actors who may help the box office:
Tom Hanks would be quite a coup.
A few years ago, Daniel Craig said he wouldn't mind being in a "Star Trek" movie. I think Craig would make an interesting Vulcan.
Either Ben Stiller (a fan) or Ricky Gervais would be a neat choice for a Harry Mudd-type of villain.
I agree with King Daniel that Johnny Depp would work as a Q or Trelane type of character. Almost too on point, really.
Craig wanted to be Finnegan at one point, IIRC.
Stiller, Jack Black, and Gervais would have been amazing as Mudd, but Mudd was already dealt with before STID, so that's out (unless the Mudd in question was just the daughter of Mudd, and the real guy wants revenge?)
weird how only a few are mentioning women including me. some females I would like to see in trek.
Angelina Jolie (she is a diverse actress)
Ann Hathaway
Jennifer Lawrence
Emma Watson
The last three would be great, but Jolie has said that she wants to direct now rather than act.