1. Start at whichever you are more comfortable playing. 25NL is definitely better from a bonus stance.

2. Start at full ring, and don't move to 6 max until you are able to develop decent reads.

3. For strategy, ya a top 10-20 hands is a good start. Learn to tighten up in early position and loosen up on the CO and the button. Learn to spot people who make continuation bets and punish them when they slow down after a call on the flop. Put opponents on a range of hands and act accordingly. Don't build big pots with weak hands OOP (out of position). Don't make bets that will only be called by better hands.

4. Party seems to be king with the vast amount of tables and fish. Paradise is fishy, and so is Pacific, OMG Pacific is ridiculous lol. But for bonuses you are better off with Party.