You cant lower your weapon in multiplayer you can only do it when you change your network settings to local.
by getting xbox live
With a weapon in Halo 3
Dying
it is a halo weapon used in the games halo 3
yes but it isn't like the halo 3 matchmaking instead it is called firefight and you and other people get to fight off wave after wave of Covenant
Yes. The sentinal beam is a weapon.
no it'll take place on the planet reach which is where Spartans were trained and when the covenant invaded it don't know about the multiplayer.
Unfortunately, you have to have a weapon.
Same way as Halo 3
you have to change to a local match and then press LB + RB + LS + A + DOWN [D-PAD] for approximately 3 seconds.
no there are no "cheats" in halo, thought many glitches
After finding a halo 3 skull, simply pick it up as you would any other weapon.