Modern Star Trek has gotten away from the Alien = Rubber Forehead formula. So you could have an alien captain that fit the normal lead actor looks stereotypes and wouldn't have scabies on his face.
Don't forget Superman is an alien, but still fulfills the all-american boy type character. You could imagine a typical Captain character which also has psychic abilities or incredible strength.
Supes looks completely human. Star Trek
doesn't really do completely human looking aliens. Last time I checked, they were firmly in the rubber forehead mold. When did they change? I'd love to think that there's some new Star Trek
out there that somehow escaped my eagle eye.
But howabout this - an android captain!!! Or maybe an augment or a hologram? Those are the three main ways to have a human-looking but "alien" character in Star Trek
How about a navigator with down syndrome and a dwarf as the engineering officer while we are at it?
Hey, a dwarf would fit into the Jeffreys tubes much better...wow, would that be un-PC.