They are randomly placed on the map. But remember that the strongholds need to be spawned at a new place where you have never been before. If you already had a big world before the 1.8 release, you have to go very far to find one. If that's the case and you want to find a stronghold, I recommend you make a new world.
Yes
I would not assume so.
You have to find an End-Portal in a stronghold. The probablility of finding a stronghold with an End-Portal in it is small. Because there are 3 strongholds per map, and there is 1 end-portal per game.
A Minecraft world seed is what Minecraft uses to generate the terrain to begin with, it does not create any user-created structures like castles, only things like NPC villages, mines and strongholds.
Ender Portals are unbuildable in Singleplayer, but if you go into creative mode, you'll find the End Portal Frames and Ender Eyes in one of the tabs, the only way to find them in Singleplayer survival is to use Ender Eyes to follow and find the location of the Strongholds of the Portals.
Yes
Chests in Abandoned Mineshafts/Strongholds, Village farms, livestock (Pigs, Cows, Chickens)
I would not assume so.
You can only find mossy cobblestone around monster spawners also in dungeons and strongholds!
xbox 360 i just like minecraft 1.6.6. and everything works seeds items anything for 1.6.6 strongholds came out in minecraft 1.8 so sadly not let in to game update said to be coming
As of the time of this answer, no. The current version is like the Beta 1.7.3 version on the PC, and strongholds were not introduced on the PC until Beta 1.8, one version later. The End portal was also not a part of strongholds until Minecraft 1.0.0.
You cant, you only get them in Dungeons & Strongholds
as of this answering date yes I think so
MINECRAFT: in which way, destroying the blocks that you put the pearls in, you cant destroy the blocks.
You have to find an End-Portal in a stronghold. The probablility of finding a stronghold with an End-Portal in it is small. Because there are 3 strongholds per map, and there is 1 end-portal per game.
There are no villages or other structures in the demo version. You will notbe able to find strongholds, jungle temples, desert temples, mineshafts, or villages in the demo.
No, but there are mob spawners and loot in the nether strongholds. Be careful in there, though - the mobs within are particularly nasty.