David

There aren't any builds based on scrolls because scrolls aren't restricted by anything a build would be based on (e.g. magicka, magic levels). In other words, scrolls are useful because any build can automatically use them. Compared to a normal magic build, you'll end up spending tons and tons of money (not feasible in the early game) for scroll-spells that are generally pretty mediocre.
 
Now, I don't say these things to discourage you from a scroll-based role-playing build. It's just that you can literally do anything you want build-wise if you plan on using scrolls.

Honestly, it's probably the same as the difference between the games. The legendary guide will include information from all of the DLCs.
 
Merry Christmas!

The only pre-req is to have completed the other Thieves Guild quests (Darkness Returns, Imitation Amnesty, Silver Lining, Summerset Shadows, The Dainty Sload).
 
After that "Under New Management" just consists of doing five jobs (probably your "mini-quest") in each hold. After you've completed 5 jobs in a hold, you are given a reputation quest with that hold. Complete one of those for every one of the four holds and Under New Management is completed.

If you don't have a save you're probably out of luck, unfortunately. Items should stay in the stores for two in-game days if you do decide to go back.
 
I accidentally deleted my Dawnguard save before using the bow, so I know the feeling.

I've heard of that happening. You can check to see if it was completed by looking under Quests in the start menu. As long as you were able to get another quest from the Companions it shouldn't be an issue... The problem is that sometimes the same thing happens when a quest is required and you aren't able to advance after it.

I'm not familiar with the sanctuary/shrine you're talking about, could you be more specific? If you're positive you are unable to go back to the sanctuary where you stored your masks, you're probably out of luck unless you re-load from one of the previous saves. If you haven't done too much after losing the masks, you should still have three auto-saves to load from. Of course, these are overwritten every time you enter a new area of the world (or a house), so chances are you've missed that opportunity. You'll probably have to decide whether or not the masks are important enough to you to have to re-do a lot of your game to get them back.
 
If you have the game on the PC, you will probably be able to use console commands to work around it (though this is not an option if you play on the PS3/360).

Unfortunately, no, you can't stay at stage three for very long, and stage 4 is what it is because NPC's are hostile. You could potentially mitigate the hostility by using "Calm" spells, although this wouldn't be practical in areas with many NPC's. Stage 3 lasts 24 hours; after that, you progress to stage 4.I'm not sure if you've read our guide on Vampirism or not, so I'll link it just in case my answer doesn't cover all of your questions.
 
You should consider creating an account here. It comes with several benefits, and also makes it much easier for you to post questions and answers. It's completely free!

Unfortunately you are unable to change your race after having started the game, assuming you're talking about changing the race of an already existing character. If you want to play as a different race you'll have to start as a new character.
 
The videos out that show people changing their race/gender/etc are people using console commands/modifications on the PC, something that is impossible with the consoles.