I'm not trying to change your mind bringit, but don't base your thoughts on two strokes by the probs you had with what was probably a cheaper model string trimmer. I too had probs like that with my initial weed wackers before I went out and bought a quality machine. With all my 2 stroke engines I have now (7 of them) I use only premium fuel and add Seafoam to all my fuel mixes. My Echo trimmer for example is now 6 years old and still runs like a charm. My 1972 6hp Johnson has had one carb kit and a couple of impellers in it's life apart from regular maintenance like lower unit oil and plugs.
Basically what I'm saying is that there are literally millions of two stroke engines out there. With proper maintenance, using good fuel and making sure to drain fuel out for the off season and running the carb dry for outboards after use they are very dependable engines.
Cheers