Well, I believe what will change is the warlock pick from the last 2 ranks so yes you can just think about it later. Also I guess it’s also true that no one actually manages to have their main be their first ever character in this game so it’s better to just play it, try to see if you’ll enjoy it in the long run and then think about what character you want to really invest in later on when you figure out the game more lol.
EDIT: you can wear costumes from previous ranks you’ve picked freely, and any premium or event costume that your class can wear
EDIT2: braindead build is more for farming, it’s actually kind of weak for world bossing and ET. I forgot to say that sorc2 is rather slow on the single target dps department, it’s the pyro+warlock class combo that lets me contribute in world bosses (and this one is a lot weaker than the wiz3-ele3-warlock2 cookie cutter build when it comes to pure dps). However at this point it will be high investment builds that really shine over others, it is in low investment that I find sorc2 to be a really nice and safe pick