Martin, I think you may be doing yourself a disservice by composing text and translating it as you are. In writing it down incorrectly, you are reinforcing grammatical errors. I know the feeling, but you are too far ahead of yourself if you don't know when to use genitive with numerals. I'd rather see you making your way through workbooks, which are designed to give you the language in meaningful doses. My opinion.

I think your sig should read Пожалуйста, исправьте мои ошибки.