Haven't heard back on question about limit to number of quilts you can post. The number is pretty high though, and if they are only ones that you have made then that is a limited number. Again, if it is not your quilt then you need permission to upload someone else's work and definitely give proper credit to the maker. If it is a photo from a public quilt show, I think you can upload without specific permission. Careful though, sometimes museums or private collections will state no photos allowed or state that images can only be used for private use or enjoyment, not to be shared online or published.
Kathy