In my opinion, psytrance is a very open genre. So it can be complex or simple as the composer wishes. By example, there are tracks with phrases of 8 or even 16 bars, this is pretty complicated because it's necessary to solve chords sequences and harmonies, this is possible only with musical theory knowledges or a great ear sense (and obviously practise). About the structure, i think all musical genres has structures to make music, despite this psytrance is more free because doesn't have the popular structure (intro-verse-chorus-verse-chorus-chorus-final), psytrance is "more linear" and this means that you probably won't listen the same section twice in a track. So the composer needs to work more on his structure, but this also means gives more power to innovate. But, on the other hand, there are ways to make psytrance tracks using some "formulas"and maybe that's why sometimes we can think that it is very simple. But obviously, simple doesn't mean bad, make that a simple track sounds cool could be pretty harder than do it with a complex track, it's relative. Have you ever seen this video? I'm not agree at all, but there are some tricks to quickly make a psytrance track. PD. I'm not english native speaker, sorry it there are mistakes.