possible trailer explanation

[voss749]

The two characters in the trailer appear to be the actor cast as George Kirk and the other character the one played by tyler perry. The construction scene would be several years before the setting of the movie.

 

[Jackson_Roykirk]

The "goggle-guy welder" in the trailer is named Anthony Vitale. He's not in the film (as of yet). Here's a story on trekmovie.com about Mr. Vitale:
http://trekmovie.com/2008/01/21/teaser-welder-talks-trek/

I don't know of which other character you are speaking.