As long as you have a website to go with your files, it'll be fine. If it's just wallpapers with no website, it'll be permanently suspended for file hosting.
1. Yours to give away or sell. Either you made the images or they do not carry a restrictive copyright.
2. As calsitoy said, they must be part of your site. You cannot store them to be displayed on other sites with lower bandwidth and/or storage limits. This is not imageshack or photobucket. This is also not an external hard drive or backup site for your computer.