I only think a couple are. I know the pictures taken of you at Test Track at Epcot appear on your photopass account. I think there is one other ride that does, but I can't think of it right now. I'm sure someone else around here will know. But the majority of the rides don't.
You can add Test Track photos for free. If you buy certain types of Space Mountain photos separately, they will show up on your photo pass CD. All other rides aren't connected to the photo pass system.
Yes. Test Track can be added to your photo pass account for free (but you'd need to buy a photo pass product, like a CD, book, print, digital download, or calendar) to get a copy. Space Mountain allows you to buy digital copies of your ride photo, which can be linked to you photo pass account. All other rides do not currently have digital photo options (I don't know why not, and I really wish they did...).