@eugrus Your German is excellent! The only thing I can say is, that it sounds a bit unnaturally (e.g. we normally don’t say " Stimmt es nicht?" - but it’s not really wrong). Your orthography is better than the one of many Germans :).
If you’d like to have texts corrected, you may submit them to one of our German tutors (e.g. Vera, alleray or myself). I - in any case - would be glad if I could help you.
BTW: Wenn Du möchtest, kannst Du mich auch gern duzen.