It's fairly straight forward unless you want to try an exotic build, as for respecing(via orbs of regret) it's way to early to say it's to expencive...the game economy is limited atm with it being a closed beta...once it go's OB prices will fall eventually, not even mentioning what they may put in the cash shop.
Even if you do fuck up you have 23 char slots and a shared stash to make leveling a new char even easier.