Definitely cheating but it sounds like he rebinded his melee to a mouse button which explains why he asked what it is on keyboard. But yeah the snaps and stuff are obvious plus the M&K controller thing
Yes they patched it out early after the game came out on xbox. This game is a port of Halo 2 circa 2007 and therefore doesn't have the sword flying glitch. If you want to use that glitch you'll need a copy of Halo 2 for xbox that is version 1.0