Is it possible to make it so the Imperial Guard don't have any troops, only vehicles?
And would it be possible to seperate them from the Regular Imperial Guard so you can have Imperial Guard and the IG Vehicles as a different race?
you could but that would take a lot of work instead you could go download this and play on armoured war http://dawnofwar.filefront.com/news/Expand_your_DoW_experience_with_new_Win_Conditions;29161
What patch do I need to play that?
its new so i would guess the current 1
Revival?
Is there any actual way to make a tank only IG?
use the sdk tools :D atribbute editor, and edit some stuff, delete, edit, delete...