Better yet, why not just read the thread that's stickied at the top of this forum that has the entire Foundry EULA spelled out, as well as quotes to every post that StormShade and WishStone have made about the Foundry Rules:
See, in that thread you'll find StormShade's post: "I've been informed that we're not allowing the appearance of characters from the shows in The Foundry. Likeness/copyright issues make this very difficult to allow, and we need to go with the, "Reference is ok, physical appearance is not ok," in order to comply with the rules we're being given."
Which means the answer to most of your questions is "NO." You can't show Picard even if you don't call him that. You can't show Ambassador Spock even if you don't call him that. No physical appearance means no physical appearance.
However, if you were to show a young man named John Jellico, who's obviously not Captain Jellico from the TV show, then that would be fine. You can also recreate your own Star Trek episodes, it says so right on the Foundry page. So if you want to re-create your favorite Star Trek episode you can, you just cannot use any of the characters that have ever made an appearance in any of the episodes and movies.
Why is it that no one ever reads the stickied threads?