Armor Lock isn't overpowered. You just suck at Reach :)
Reach isn't bad, you're just a BK :)
For my gamertag, look up "Ghoulishtie"
No.
Halo 3: ODST will come with 2 discs. The first will include the new ODST campain, firefight, and I guess a theater mode.
The 2nd disc is simply the Halo 3 disc without the campain, but with all multiplayer maps. (including the new 2nd mythic maps) Everything is exactly the same in multiplayer besides the 3 new maps (which do not support anything ODST wise)
Simply put, ur only considered 'ODST multiplayer' is firefight. Still spartans vs elites, still same ol' multiplayer.