I sent photocopies of all supporting stuff, it was fine.
For cards I also included a photo of the card, because the photocopies turned out pretty bad and I wanted it to be clear that they were actually cards. We also sent original boarding passes, again because of crappy photocopies.
Keep in mind that you don't know if you'll be getting anything back. They usually return photos and cards and such (we also got the boarding passes back), but there's no guarantee it will return to you, so don't send anything that you can't spare. If cards have sentimental value and you want to keep them, send photocopies. It's also a good idea to send photocopies or at least make a copy of everything you sent, in case you might need it later - nobody plans for it, but if there's a refusal, you might need this stuff.