Very long conversation but every other cruiseline accepts the gratuities at the end after service has been provided and is acceptable as is how grat's are supposed to be provided. If you were asked to tip at a resturant and then stand in line to ask for it back if you recieved poor service would you hand over the cash? Me either, so why should you do so on a cruise? Could you be double dipped at the end and have to fight through Guest Relations? There are many many other reasons but to save time here, if you like the system do it. I never will and clients who book through me are advised not to do so.
Happy sailing, Neil