The Elder Scrolls IV: Oblivion

yes

the skeleton key is rewarded to the player upon completion of nocturnal's deadric shrine quest

No...there is no way to get infinite health in oblivion...the cheapest way to stay alive is too multiply LOADS of health potions and hotkey them...

Per the Book Glossary at Powell's Books: Library Bound:

A sturdy hardcover binding produced to withstand long-term use. Most Library Bound books do not have a dust jacket.

drill the lock out

In "The Elder Scrolls IV: Oblivion," the most expensive item is the Master's Mortar & Pestle, which is an alchemical apparatus. It is valued at 50,000 gold, making it the most valuable non-unique item in the game.

Assuming you mean spell scrolls, both merchants at the Mystic Emporium in the Imperial City Market District sell some. Check the Mages Guild branches in each city, they have scroll selling merchants too.

Once you've chosen your class that is what you'll play as for the entire game.

You can finish this quest more than one way. You can dispose of Roland and get your reward from Seridur (just murder Roland in his cabin). Or you can talk to Roland and decide to murder Seridur instead, in which case you go to his cave hideout and kill him and his vampire chums. How difficult this is depends on what your character is like and where you have set the difficulty setting.

If you have no infamy then you don't have to lower your infamy because you can't. However, you still have to visit each wayshrine so that you get a vision from Pelinal Whitestrake. While visiting the wayshrines would usually lower your infamy to zero, if you have no infamy then it doesn't affect your infamy in any way.

It randomly appears in the inventories of blacksmiths and general store keepers.

They are hidden in the chapters.Also if you want to get the upgrade you need more happy gold.

Simple. Buy a open lock spell. You can have a open very easy lock, easy lock, average , hard and very hard but no "needs a key" Go and see the arcane university or a few shops. If you are in the dark brotherhood. That guy also sells "an unwelcome guest which unlocks easy locks. i got an open average lock from that guy in the arcane university. But You need to improve your alteration skill first by unlocking manually although I don't theink you have to with the easy lock spell.

WARNING! SKOOMA DAMAGES YOUR INTELLIGENCE!!!!! THIS MEANS YOU HAVE LESS MAGIKA AND LESS SPELLS WILL BECOME AVAILABLE!

My guy had skooma to make him stronger but later did I realize I would have to spend ages build back up my intelligence.

go to league and apply

Simply go to any area that has a group of vampries inhabiting it, such as bloocrest caverns near skingrad, and let them hit you until you contract a disease known as 'porphyric hemophilia'. At that point, sleep until you are a vampire. (waiting does not work). this counts for all races.

You're possibly trying to mix two ingredients which don't have matching characteristics, or, which have them, but you don't have high enough alchemy skill to unlock. Each ingredient in the potion/poison must share a characteristic with at least one other. So one with Restore Health, one with Restore Health and Restore Stamina, and one with Restore Stamina would work fine. Two with Restore Health and one with Restore Stamina, would not.

To kill any kind of ghost or spirit in TES 4: Oblivion, you need to either use spells, or enchanted, silver or daedric weapons.

I have tried it myself and it is great, I believe it adds werewolves to certain places of Cyrodil, and there is a ritual for becoming a werewolf. However in this mod the werewolves are called lycans. This mod also enables the opportunity for you to become a lich.

Not the one at Kvatch, but the ones found randomly out in the wilderness do.

But if you have completed the main quest they never open again

You are not supposed to be able to do so, but there are ways. 'Damage Fatigue' and 'Reflect Damage' enchantments can do it, in unpatched versions, Wabbajack can be used to make him killable. By using mods, it is possible to make a weapon capable of killing him - however his model does not have a proper death animation, so collapses and deflates rather comically if you do so.

no

You will probably get arrested, in which case you can pay the very minimal fine, go to jail or fight the guards. Paying the fine for an assault is very easy.

Only after installing a mod that someone made.

Simply because Oblivion couldn't fit in the UMD because it's graphic content is too good for the PSP.