I would do some research. I looked into it back when I was playing and most players were using a virtual solutions to play on Windows.
Why would they do this?
You could have skipped the practice league at any point.
Oh I know, but I need the practice
Though considering that all of the practice maps start you off with a blocked choke, I don't think it's really very good practice for the "real" world.
That is a game you have to play every day if you want to be good. I only got up to Platinum League and it was impossible to maintain unless I was playing regularly.
Oh I know, but who cares? I haven't started my placement matches yet, but if I end up in the copper league just dicking around, so what? I'm playing for fun, not to be the best. Everyone knows the cyberkoreans > all anyway.
Protoss 4 lyfe, yo!
Eh. I find Protoss to be the least flexible, personally. Terrans used to be my comfort zone but I am playing a lot more with Zerg these days and find them much better for reacting quickly to changing battlefield conditions. They also share the Protoss ability to build static base defense without using up supply (Terrans' biggest weakness, IMO). Then again I mostly play co-op vs AI and practice games (so far), so what the hell do I know about it?