Here's the questions I posed to RCCL:

1) Is there a fee for getting a cash advance at the casino? Does the cash advance just post to my cruise account? What's the limit for the cash advance?

2) With the cash advance, do I have my choice of Euros and USD? Or will it automatically be USD?

3) Can I cash USD Travelers Cheques at the casino or at guest services? Euro Travelers Cheques? If so, what's the fee?

4) Lastly, can I convert USD cash to Euro cash at guest services? If so, what's the fee?

_____________________

And here's the response I received:

Seapass Card
Guests may use their Seapass account for up to $2,000 USD per gaming day in the casino to purchase chips or slot tokens, with credit card backing. The maximum amount depends on their credit card limit. Guests preferrimng to not use credit card backing but rather set up a cash account, are entitled to $100 per gaming day in the casino.

Credit Cards
Guests may also purchase chips or slot tokens with a Visa, Mastercard, American Express, Discover or Diners Club credit card from the casino cashier. The maximum amount depends on the cardholders credit limitations. A 3% charge is added to those using a credit card ( not Seapass ).

A casino credit line can be arranged in advance of sailing for those guests wishing to gain an additional line of credit of $5,000 or more. ( Guests should be reminded that they can use their Seapass card for $2,000 a day, and if they decide they need more, the credit line can be arranged prior to sailing.) It is automatically in US dollars.

_______________________

They didn't answer my questions about changing USD to Euros, so I'm going to send them another email. But this is definitely a good sign. This will be a great way to get money while I'm on the cruise, and earn miles to boot.