I'm pleased there are a few post regarding this on here! Like everyone says, once you get into the game there are certain aspects of your character that you wish you could re-do as no one wants to start over if they've poured hours into the game.
I use and Exo and all I would like to do is re-colour his face, I was happy with it in the beginning but when you see it in the game I'm not that keen anymore.
Surely just allowing us to edit our characters at the login screen would be a start :-)
The exo race gives us even more world building opportunities, too.
We've seen how humans have modified themselves aesthetically, but what might an awoken do to change her appearance? Or an exo? Might an exo titan weld a piece of a crazy minotaur he killed onto his body? Are new paint jobs like tattoos? This offers some interesting cultural background that can tell us how different and similar each race is to one another.
It may seem petty, these surface changes, but how we modify ourselves is certainly a reflection of ourselves and our culture.