I was also thinking of this - you can set price on bandcamp for an album to a minimum of 0.00, but not just tick a box and say "free" (it's like they want you to make money or something…)
I say keep an eye one it, and see what happens.
edit: Oh, yes. Uploading images can be done by logging in, then scrolling down to the bottom of the page. On the right is a row of green links:
Edit Tags History Files…..
Click the Files and a list of the attached pictures will be shown. Scroll to the bottom of the list, and you will find Upload a file from your computer Click that and away you go.