yes
yes
the halo reach legendary edition comes with extra armour for Spartans and elites as well as a model of Nobel squad
You can't be a hunter only Spartans or elites sorry it would be fun though
Choose the gamemode Slayer (Not Classic Slayer) and play that one, or choose invasion, to play Spartans against elites, or choose infection, for Spartans and elites to fight infected Spartans and elites. there may be other ways, but they are not yet known.
No. You Can Only be Elites and Spartans.
Short answer: bad. In Halo: Reach the Elites (Sangheili) are fighting for the Covenant. This is rather confusing to many players as they were allied with the UNSC in previous Halo games, but keep in mind that Halo: Reach is set before even the first Halo game, Halo: Combat Evolved.
No. In Halo 3, you can only play as Spartans and Elites.
In Halo 4, you are not actually fighting the real Covenant. Instead, you are fighting a rouge group of the Covenant known as "Storm". This rouge group still believes in the Prophets' teachings. Not all Elites are part of Storm, only the ones that still believe.
The higher your rank the more armor you unlock for the elites but you cant customize elites like you can with Spartans
Halo: Reach happens before Halo 3. The Elites haven't defected from the Covenant yet.
What is important about the gold ranger on halo reach