What happens a week later when I put the sim back into the BB?
It basically picks up where it left off.
Will hundreds of emails come to the BB?
Yes. They will be pending on your BES to be delivered once you resume communication with it.
Will the calendar requests, which get automatically accepted, appear on the phone magically?
What about the gmail that gets forwarded to the phone?
Same as your BES mail. It will flood into the device once you have a data signal again.
I kind of think everything will should just OTA synch and there won't be any problems
That should be the case.
Is the best thing to do if all of the stuff comes to the phone just do a DELETE on Handheld, and then go back to outlook and gmail and read the originals?
Only you can answer this one. That would be one way to handle it, and probably what I would do in this situation.
Enjoy the cruise, eat lots of food.
Don't drink too much as to cause you to not remember your trip.
Use lots of sunscreen.