[Dazarath]

0. This should go in the Small Stakes forum.
1. This depends on you. If you're a 20/40 Omaha player, it may be hard to go start off playing 2/4 Hold'em. I'd probably suggest starting a little lower than what you play for Omaha. Always be willing to admit that you may not be a winning player at a given level (since you're new) and be willing to move down if necessary.
3. Online, all of the limits are beatable. The rake is not as ridiculous for small stakes as it is live.
4. Most people here play on Party Poker. Rakeback is always a plus.
5. There are players who find 1/2 tough and there are players who find 30/60 a breeze. I can't answer this one for you.
6. There's no set cutoff. In general, as you move up limits, the opposition will get tougher and the fish/TAG ratio will decrease. Always use good table selection.