I'm gonna address the checking your
bankroll question first.
Personally, I think you should work real hard to not do this. But it's bigger than just "not checking while you're playing". I believe you should stop looking at it as money altogether, at least in the day to day playing poker sense.
I think most of us benefit by concentrating on making good decisions.. not focusing on winning or losing pots/money. You simply can't judge a hand, or even a session by the money. The money alone
tells you almost nothing, and getting distracted by the money never helps.
To that end, try to play stakes where you are appropriately bankrolled, and some swings either way don't have to concern you.
As for reviewing
hands.. if you have Pokertracker/HEM.. mark any hands as you play them if ANY of the following are true.
1)At some point in the hand, you were unsure what to do
2)The results of the hand was unexpected
3)You lost "because the other guy played badly"
4) You folded/lost in a fairly large pot
5) You had a premium'ish hand (TT+AJ+) pre-flop, yet lost the hand at the river.
That should give you a good starting point for hands to review.
The real trick about reviewing hands is to get the opinion of others. This is where posting hands to forums can be helpful.. but reviewing with a friend/mentor can be even better if that's an option.
Listen to the opinions of others, and consider the logic. You don't have to end up agreeing every time.. but try to understand their reasoning before agreeing or disagreeing with it.
Often you still aren't clear after reviewing hands with others or reading the forum post responses.. but in time you will become a better player for forcing yourself to think about the hand and consider the advice of others.