No, the only teams you can be in Halo Wars is the Marines and the Covenant
No, the only teams you can be in Halo Wars are the Marines (humans) and the Covenant.
In Halo Wars you are not in the army you just control it, but if you are on the covenant, and you are the abritter, you can control him as his special.
covenant & flood
Yes, in Halo Wars you will be able to play as the Covenant. I dont know, however, if you will be able to play a story mode as the Covenant, but I know that you will be able to in Free Play and Xbox Live.
No unfortunately you cant
no... its before Halo 1 when the humans have just started fighting with the Covenant
Halo Wars is about 20 Years before Halo Combat Evolved. So the Elites are part of the Covenant.
You build a factory
no
Yes. There are Arbiters, and other Covenant aliens!
In my personal opinion Halo Wars. In Halo Wars you can get a better feel for the Covenant and learn more about the UNSC histoory in the Great War and learn more about its troops.