How do you license the photos? is that something that needs to be taken care of by a lawyer? Just cause you say you can only print up to a 8x10 and everything else must go through me how is that going to to stop someone? do you just limit the file size so it will look like **** after you go above 8x10?
Wal Mart is very careful about asking you for your release from any image that looks like it's professional. EVERY lab should be and they're getting better but, there are those that won't and will just print it.
A release is a written, signed document that states what the client can do and not do with their images. It will include the photographer's infomation, the file names/numbers and the date they were created, the release information detailing what can and can't be done with the images and the photographer's signature.
I give it to the client in both print form and on their disk. The disk contains a PDF of the release as well as an image file so if they go to have prints made and are asked for their release the lab or store can pull it up either way.
I also include the release information in the exif data of my images.
My images are cropped to 8x10 at 300PPI. Will it look like crap at a larger size-depends on HOW larger and how the image is viewed. If the lab is doing it's job, they will not print larger.