re: Poker & New Game Theory
The stuff you're saying is very general. You need to find out what and how much *you* need to learn to be competitive now. And that depends on what you know, how you used to play, and the level you want to play at now.
For example, the game is generally looser than it was a few years ago. So, it will probably be a bigger adjustment for you if you were tight.
As well, the play has changed more at higher levels, so the lower you want to play now, the less you'll have to learn and adjust.
You might want to go spend at least a few hours watching games at various levels, with an eye to assessing what and how much you've fallen behind the curve.