[Death by Mirrors]

Personally I think the main goal at roleplay is to have fun, not to be super awesome good at it. Of course I also get what y'all mean about being really critical. Hence why I sometimes hesitate to RP in English, even though I think my grammar is decent at least (but these two or three times when I picked a wrong word are the ones which tend to stick in my mind).

Sooner or later I want to go back to pen and paper roleplay via roll20 - of course, an actual round around a friend's dinner table would be cool too, but I always tend to have friends who either live in another country or don't like RP much.

Maybe that's an option if you hate writing or are conscious about your work's quality. It's pretty much just building characters and then describing what they do and/or dialogue. If you don't know what to do, there's always the players guide to back you up. Either way, fun first. Quality comes with practice.