Race has such a little impact that nobody gives a trout. It's like 0.01% of what will make up your character's ability to tank/heal/deal damage. Nobody will ever care. Seriously. Races are, essentially, purely an aesthetic thing. You will be able to (and most people do because it's far more efficient) have one character be every class, and you will have to level each class up seperately (changing classes is as easy as changing weapons... in fact, that's exactly how you do it). When making your character, the only thing you need to think about is whether or not you like the look and sound of your character. That's it!