I dont know if you mean exclusively online or both that and live. I assume you dont use a HUD.
There are so many articles on odds and such, google, look here in the strategy articles, and it really isnt that hard to do basic odds and outs. It takes a little time, and practice. But that is only the beginning.
You mentioned a player raising pre and post a lot. Of course, your relative position to him is important, but this kind of players could be decent and aggressive, or could just be a manic. Your best strategy vs. him is to also be aggressive, but with a plan. Like if you are in position (IP) 3 bet him with a wide range, like Axs, Any BW, AT+, SC - maybe 56s+, any pair. If he folds, you can start playing back more often till he starts 4 betting. If he calls, see how he plays post. If he always leads, reraise relentlessly. But if he is a manic, you will be flipping a lot, and IMO you should be willing to GII with any PP 88+, and post with any decent draw, big pairs, and maybe even one pair with BD draws.
What I just wrote is very overly simple and in no means a strategy in and of itself, but, to answer your question, yes, you are being over cautious. Folding AA to a bet post is very bad, unless you are folding for a reason. Cause he could have 2P is no reason. If he only bets with 2P+, a good reason.
Your reasoning that "he cant have good cards all the time" is spot on. Abuse him, and he will adjust vs you if he is good, and he will give you money if he is a maniac. You stayed out of his way. He was aggressive. It seems everyone else stayed out of his way. Imagine YOU play aggressive....... You get me???