beating the campaigne on legendary is a fast way of unlocking most the armor. some achievemnets also unlocks armor.
There is no Brute armor in Halo 3, only Elite and Spartan models.
certain achievements give it to you
We can not answer. You must have had to pr order halo reach to get elite officer armor.
No, only elite's.
you will get elite flight armour
I assume you are asking if you can customize your Elite armor in Halo 3 multiplayer to include the katana? No you cannot.
All the armor are the same it's just the way how you want to look WRONG! the best armor in halo 3 is the recon armor and you have to be a member of bungie OR get all 7 vidmasters in halo 3 ODST
http://halo.wikia.com/wiki/Armor_Permutations look here.
There is no way to get and different armor for Elites in the BETA.
lt.colonel
You simply have to reach the appropriate ranks. The Elite armor does not cost any extra cR.
Yes, you can get recon for a 'spartan', yet none for an elite.