re: Poker & Analysing 2nl Position stats
you can't possibly expect your line to go up vertically, can you? 7.75BB/100 (=15.5bb/100!) is a very respectable win rate, even at 2nl. you are probably ready to move up to 5nl soon, aren't you?
most things are as micromachine said above - play more hands in later positions and fewer hands in EP. steal % seem OK, especially if those steals work.
as for making changes to your game (e.g. 3-bet lighter) - do what you feel comfortable doing. there is no immediate need to start doing this, it has to "come to you". you win plenty as it is, you could try a few more things, say 3bet QQ and JJ from late position or AQ against a light blind-stealer, and see how that works for you. eventually, you will develop a feeling about what works and what doesn't.
unfortunately, those things change with the limits, so if anything works at 2nl, that does not mean it will also work at 10 or 25nl. this is the entire purpose of studying your game and that of the opposition. to find things that work and eliminate those that do not work.