Its easy to convert files, but yes higbey ive had to cope with my... Mac.. Aswell, i hate it. None of the games i want to play work on it, half of the steam games dont work with mac, and everything achievable requires extra hassle to do. For GFXing i use paintbrush, its basically paint.net with your transparencies and colour wheels, GIMP works aswell but i find it more difficult and frustrating to deal with. Also MAC WAI U NO HAVE ROTATE IMAGE. I also found it amazing that macs are for graphics/movie making, yet imovie sucks as the default moviemaker and there is no default paint app.
Also itd either called paintbrush or paintbucket i cant remember i just googled paint for mac .