There isn't one, sorry.
From Morrowind at least, completing the main quest does not end the game, you're free to roam around the world completing side quests and whatever, after you complete the main story.
The rewards? Which rewards? There are hundreds of sagas/quests/cutscenes for which you obtain rewards. Which one? And what do you want to do to them?
You get it near the end of the main quest.
you must play the Bloodmoon main quest and you will get accepted during it.
In Habbo, the Lifeguard Quest typically involves completing a series of tasks related to beach safety and helping other characters. Players often need to collect items, answer questions, or interact with specific NPCs. The exact steps can vary, so it's best to check the latest guides or community forums for detailed instructions on the current quest. Completing the quest usually rewards players with special items or badges.
for completing the quest you get 1 quest point
You can only be one kind and you become naked. when you beat the quest you get a ring that turns you into a werewolf.
Click on the related links, for a list of special quest rewards.
I don't know about Arena, Daggerfall and morrowind but in Oblivion you need to start the last thieves guild quest 'The ultimate heist' and in skrim it is part of the main quest.
the word is leagues
there isn't a flying boat, but you can obtain a ship after completing the Bloomingdale story and the starflight express after completing a post-game quest
you can purchase it after completing the dragonbane quest.