1. No Shepard. It's not because I don't think Shepard is an interesting character, but mostly that I wouldn't want to tell folks who love playing the games that this is how Shepard should behave and act. Last thing I'd ever want to do is pull another "Revan is male and is light side in canon". Shepard should belong to the players.
To be fair, to a certain degree this is what happened in ME3 anyway, with all the AD, and THAT ending.
Definitely concur with no Starbrat/Crucible though. If they went down that route I wonder if they'd continue to build up the "We can't win conventionally" message throughout, thus necessitating a different deus ex machina plot device.....