Hi Creto, welcome aboard.
Most of us are not professional, we just like to play with Gimp and Inkscape. In fact, when I started out I only knew how to play with Gimp. But last summer I taught myself how to use Inkscape because many people here recommended it. So just being on the team has taught me new things, and has been a positive experience. I hope it will be similar for you.
I was very impressed with some of the wallpapers you made. Hopefully once Mageia 2 is released we will get some server space and a digital gallery to work with where we can showcase all our work, yours included, for people to download.
And don't worry about the English.  For most people on the team English is not the first language, so we're very patient and tolerant.
Max