These are great ideas Wombat, doing the Brits proud!
There are so many awesome possibilities if Relic were to add the British into Company of Heroes 2, not just with units and doctrines but with skins, voice acting and the overall feel of the army.
There could be an SAS commander that allowed you to call in an SAS Jeep loaded with commandos with all sorts of abilities armed with Stens. Or there be an RAF/Airborne Doctrine that allowed for Typhoon runs, Supply drops (With a chance of Red Berets of course) and so much more.
Relic have to capture the essence of the British army during 1944-45 which I believe was an effective, mobile yet cautious beast capable of beating back anything that was thrown at them through the use of various elements within the company.
What would really be interesting is if Relic actually did the African Theatre of war, then we would have a truly unique faction when talking about the British. Crusader tanks speeding through the desert flanking Panzer III's, Infantry rushing through barbed wire assaulting fortifications and tanks. The Afrika Korps as I see it would be a faction that was flexible and tough, but also vulnerable in terms of supply. I'm just rambling on now but there truly are so many possibilities with not just the British, but with every other faction.