Wait, can you transfer all your XP from one char to another or no?
http://www.fragworld.org/frag/community-blogs/brink-info-pt-3-weapons-and-customization.html About half way down the page...
"If you create multiple characters, you can transfer XP from one character to another; so if your first character has a lot of extra XP and you want to level up a 2nd character really fast, just give him some XP from your first character."
"When you first create a character, you choose stuff about him that's permanent, which you can't change later (skin colour, voice, face, tattoos & scars)."
Permanent tattoos I can live with as long as I can see all the tattoos at the beginning, that way I know which tatts I want and can hold off until I have unlocked them. Looking at the screen shot posted by "Capt. Awesome Man" my guess would be that we will be able to see all opitions at the very begining, just not being able to use them till they are unlocked... guessing of course and also hoping.