I know very little about Redbubbble, and I guess Dianne has explained it the best.
But the problem that I see is this.

Firstly, the selling a couple of Poscards here, and an odd Teashirt or Teatowel later on
is realistically not going to be of much benifit.......really
(And a big difference to the price that my friend sells his stuff for.)

And secondly...... when and if you decide to pull out, they still have a copy of your photos uncondensed.
So......even if you ask for your work back.........it'll probably only be a copy anyway.
And what if they decide to use it.........then what?
Firsty what are the chances of you ever seeing it?
And if you do.........then what?
Your solicitor will have to write them a letter asking for it's removal.
So your photo of Mt St. Clement will be removed and they will simply replace it someone elses photo of Mt Clair........for them no difference.

Well that's my view, you may think it a little harsh, but that's the real world out there.
Everyone steals computer programmes and they think that thats OK.......it's just the same.


Cheers,
Joseph.