1) Generally if the project is working in a currency outside the USD it will not go through Amazon but directly through your CC.
2) At the close of every project you will receive a basic survey through KS. It will require, at the very least, your mailing address. Some projects run another survey through an outside service such as Backerkit or Pledge Manager. These services would often allow you to add on more items after the project closes.
Hope this helps but feel free to reach out with any other questions.
EDIT: The only dumb question is the one you don't ask! Feel free to PM me if you are embarrassed to ask something in a public forum. I enjoy helping out the Noobs the best I can! Bear in mind though that these questions and answers may serve someone in the future if posted in public.
A most excellent answer!
So far, KS works in five currencies that I've seen: US dollar, Canadian dollar, Australian dollar, British pound sterling and the euro. If you aren't in a country using one of those currencies, you can't launch a KS project without having a business partner in a country that does use one of them.
When you see a currency other than your own country's being used for a project, check carefully on the cost of shipping - in most (but not all) cases, they'll be shipping from a country that uses that currency instead of yours, so you'd be considered "international" on the shipping rates, not "domestic". A notable exception would be the upcoming "Empires Bloodline" deck, which you pay for in Australian dollars but will ship from the US.
Also keep an eye on the payment method used: bank account, credit card, debit card, etc. - your bank will probably charge you a fee for purchasing in a foreign currency, similar to if you went to a currency exchange but usually slightly higher. In my experience, the fee is often in the ballpark of 1%-2% of the amount charged/paid.