Marcie, I would call number on back of your Amex Platinum. I don't know if you need to wait until renewal date. You have to contact Fidelity to get their Amex Platinum and will it be tied to your brokerage account. Only negative is that funds are automatically transferred from your Fidelity cash account the day after the Amex monthly billing cycle close date; i.e., no float period.
As for cruise credit, Ngaire could find out. I assume it is not a problem substituting one card for another.
