I think I'm comfortable enough with poker now to start investing my money into online games with the aim of having a slow trickle of money coming in (over time). What are good stakes for me to play at? I notice the lower stakes play like idiots and are really unpredictable and overly aggressive. It feels like at low stakes its all about luck... High stakes could be risky for me if i go through a bad spell. What do you thinks a good balance? What stakes to semi pros play at? Am i better off only doing tournaments? If so what kind of buyin/prize?
Microstakes are considerable tougher these days, no matter the game type, either cash or tournaments.
About the good stakes to play, you need to check your poker bankroll. Do you have more than 100 buy-ins for the tournament stakes you're planning to play? Then play in that, while recording your results carefully, especially the winrate. And do this for thousands of hands or hundreds of games, depending on your game. This is the only way to realize your skill.
This is for your bad spell you're talking about. Everyone has a bad spell (btw, this is called variance and it's a good thing; it keeps bad players in the game). Be glad these aggros keeps shoving their junk or overcalling with dominated aces, because these wins keeps them in the game. And this is probably the #1 reason why microstakes are way more profitable that higher stakes.
players in microstakes are making the most mistakes
Also, you need to have a way bigger bankroll before venturing to higher stakes, but you also need a way to realize how good you're at the current stakes, which involves some kind of noting.
All in all, record your games (some people uses spreadsheets or poker trackers), play a big amount of games in a limit your bankroll can breath with your losses. Calculate your winrate. Based on the winrate and your bankroll, you then decide where you really belong.