I think they're a few things you can improve based on your stats:

1. As you've said, VPIP is obviously too low. Try to steal more liberally first in, and possibly limp in with the more marginal type holdings from MP, etc (ie. pocket pairs)

2. You're not defending your blinds enough, but you already knew that. When defending in the SB, it's important you generally 3-bet to avoid giving BB the odds to continue.

3. Raise more preflop. Stealing more liberally will help raise your pf raise %.

4. It also appears you're not getting to showdown enough. Possibly folding potential winners on the turn and flop.

5. River aggression is obviously low, try to value bet more here. Don't be afraid to take a bet/fold line when the situation calls for it. Also try to avoid calling down aimlessly.

There's a database of 2+2 players 2/4 and 3/6 stats somewhere, though I don't know how to link. Try to compare your stats to that, to get a basic idea where you're at. Search for "Tiger woods" in the search engine and it should come up.

I don't think I really identified anything new to you, but hope I helped in someway.