No, it is paid-for DLC.
It is daedric armour!
You get it from Steam.
Yes, you can.
Dawnguard is the expansion that adds the werewolf perk tree, without that, you can't get werewolf perks.
Factions you can join: Companions College of Winterhold Dark Brotherhood Stormcloaks Imperials With the Dawnguard DLC: Volkihar Vampires Dawnguard
When is Dawnguard coming out for PS3
It costs £12.99
Dawnguard is basically an expansion pack for skyrim. like all expansion packs, it requires the base game to play. So on a PC (and any other gaming device) you need skyrim first and then you can install dawnguard.
It costs around £13.
Skyrim for Pimps - 2011 Dawnguard Begins 3-1 was released on: USA: 1 August 2012
Dawnguard will be released on the Xbox 360 on June 26 and for the PC on August 2. Because of performance issues, release for PS3 is still postponed.