no
In order to marry anyone you first need the Amulet of Mara. You can acquire this amulet from Maramal at the Bee and Barb in Riften.
Usually, to get married in Skyrim, you will need to do a quest for the person you are trying to marry.
No you can't
Isnt nocturnal a daedra? if so then i doubt it
No, there is a limited selection of people you can marry, you can only choose from amongst those.
No sorry thats a fault with the game there sorting it in the next patch
Ysolda because she will end up being an asset to you
Some do.
This sounds like a mod, not part of the vanilla game. You'd have to see what the mod says.
I don't think so if you are in the U.S.
You can marry any NPC character in Skyrim through the use of console commands. With the exception of Serana from the Dawnguard DLC (There might be a way to marry her, but I haven't found it). Vivienne is not a character who can be married without console commands.