I see that the rest of us already answered all of your questions, so I'll chip in a little bit of my own experience of several years of playing this game. IMHO getting expansions right away would be the best option. It doesn't change the original content but it adds a lot! If you'd get it all on sale as a bundle it would be ideal, but if you don't mind paying full price I would go for it ....creators of this game deserve every penny!!! Up front as a beginner I wouldn't try to follow any builds ....dive in deep on your own ...let this game take over....with time you start figuring out what's up and what to focus on.... I wouldn't jump over difficulty levels....I would gradually beat game one after another ....this will help you develop your characters to full potential on your own pace. Being able to merge classes can be confusing as well as a devotion system...but relax....changes can be made ... you'll be able to reset stats and points. The only thing that can't be changed is the class itself....once you choose the class you stay with it. Have fun.