I wouldn't have the same actors for several of the roles (Bakula and Blalock would definately be replaced).
As for the character of Travis I did consider cutting him entirely, in favour of more alien diversity (which I personally find more interesting). In reality though he could resume his role at the Helm, with the increased rank and made more of an experienced character who has seen more than any of the other humans in the cast. As Yeoman though he would be on away missions with Archer, acting more as bodyguard than secretary, as well as being a certified pilot and general jack-of-all-trades, someone who could be counted on in a crisis, who Archer could also confide in when he needed to.
Well, Travis did have more space travel experience than all the humans on the ship. It just was never properly explored. Your suggestions for the character appear to me to be more of the same, with a caveat; now a large part of Mayweather's existence is devoted to "support" of Archer.
I think you're suggesting he become one of those "confidants" that blacks and other minorities get thrown into when writers feel they are unable to find anything more involving for a black character or black actor.
Besides, Archer has Trip as his confidant and later, T'Pol. Make Travis a fully fleshed out character with more than one dimension. That was the problem with Mayweather during the show's run.