Sure! Just do the math and add it to your pledge. If you'd like three A1 sized prints for example, just pledge for the A1 size and add in the price for the other two. If you'd like to buy bulk (more than 5) send us a message.
Up to you! If the campaign is successful you'll get a survey at the end asking for which edition you'd like. Same goes for the prints.
Don't see the answer to your question? Ask the project creator directly.