Lots of people have answered for you in different ways, the confusion with move up bids is really around high end suites.
in most bids you keep your original promotions , obc, Wi-Fi etc and just get room
ameneties (ie if moving up to aqua you would get blu and Persian garden and canapés for example ) but keep your perks / promotion from original booking - I also believe you would pay the new tips (if you had tips as a promotion you would pay the difference from your original perk tip to the new top price ) the only time this gets confusing is in high end suites like the royal where the room comes with certain benefits like premium drinks , Wi-Fi , speciality dining etc - so you would automatically get premium if you only had classic drinks or no drinks ) any other promotions like tips and obc would be what you had with original booking. You would again pay the higher suite tips and if you had tips as a perk again you would pay the difference .
uou also only pay for 2 guests on the move up even if more than 2 in the room so bidding 1k each would only be 2k even if 3 in the room .
drinks in lounge and retreat deck are free so you would get those in any suite irrelevant of what you got with your booking .
the question about captains club I would encourage you to register and add to your booking so you could benefit from day 1 of earning points which do give some benefits for future cruises . Good luck with your bidding