No, in Halo 2 you can not unlock armor.
Sorry there arn't any, The only skulls are in "Halo 3" Which are used in "Halo 3 O.D.S.T."
There aren't any
yes but i am sorry i dont know where any are them are
You have to get all the skulls. and you have to jump through rings on the level covenant when you beat the aliens don't go over the bridge be sure you kill the flood and jump through the rings in this order 4 6 5 4 5 3 4 when you are done the skull should appear right in front of the bridge entrance.
there isn't any
yes but you can only find the skull if you play the whole mission from alpha point
It depends on your skills. If you are good at the campaign, go for legendary. You should get about 3-4 pieces of armor. If you are good at following instructions, there are specific goals, such as Too Close to the Sun, in which all you must do is shoot something or complete something and it will give you the achievement. If you love multiplayer, there are skulls for it, too. You can also get the "goals" achievements, doing this. Finally, if you aren't good at any of this, you can easily get the Hayabusa armor by getting all of the skulls. You can go on normal and play through the game, finding the skulls along the way. That will give you the complete Hayabusa set.
I don't believe you collect any. You just turn them on or off.
No the only way to get recon is from bungie or from getting all the vidmaster achievements from halo 3 and halo 3: ODST.
The first skull on halo 3 is a silver skull. Silver skulls do not award any achievements.
recon will become regularly available after halo 3: ODST comes out in september. You can obtain it by completing all the vidmaster challenge achievements.
== == There are the skulls, but they don't really count as cheats, they make the game more interesting or harder (press X in the campaign lobby to turn skulls on, if you have found any) == == there is also a way to lower your weapon but i dont know how