While the Geth and Sovereign are attacking the Citadel, You will be prompted with a choice to either have the Alliance attack Sovereign or protect the Council. You need to protect the council.
Alien merchants and NPCs will like you more, and you can get reinstated as a Specter by the Council in Mass Effect 2.
You won't be able to import your save game from ME1.
It just effects some interactions and choices in the game.
Yes It is possible but you have to have a paragon to be able to save her
no you cant one has to die
Jeff "Joker" Moreau is never really threatened or in need of "saving" in the Mass Effect series. This question does not really make sense.
If you played Mass Effect 1 the second game imports your old game save, so it would depend on how you played Mass Effect 1 as to whether or not Kaiden is alive. If you did not play Mass Effect 1, then the game will default to the character with the opposite gender to Shepard. So Ashley will be there with a male Shepard, Kaiden for a female one. Below is a link which has the important decisions you make in 1 and their effect in the sequel.
If you don't import a save game from Mass Effect, you will automatically choose the character of the opposite gender to survive. If you play Mass Effect first, though, you can choose if you want Ashley or Kaidan to survive. So to play Mass Effect 2 as a female and with Ashley alive, you would have to play Mass Effect and let Kaidan die on Virmire.
You do not need to own ME2 to play ME3, but if you have ME2 you can port you save into ME3, which causes choises you made in ME2 to affect the story in ME3
You can scan planets and build relationships with the characters. You can also import the save game into Mass Effect 3, or import it into Mass Effect 2 so you start at the same level as when you finished the game. Other bonuses are included if you choose that option.
yes just make sure you dont save over your old save in the menu during gameplay
Can the PC play the Xbox 360 game Disc. No of course not. They are not the same game and only have the same title. You don't even have the same title and want to save a different game in the series on a platform it will not play on
If you import save data from Mass Effect 1, then whichever character lived through the first game will be in ME2. If you don't import save data and don't use Genesis, Kaiden will be in the game, but Ashley won't.