First of all I would suggest talking to other photographers at the circuit, they will be able to tell you what settings they are using and show you the results that they are getting.
Use the centre AF point and AI Servo and focus on the riders leathers.
I wouldn’t bother with a monopod as panning is much easier without one, especially if you are only using a 70-200 lens.
As for the shutter speed, I certainly wouldn’t go any faster than 1/800 as all it will do is make the bikes look really static, in-fact I would say you should look at lowering the shutter speed. But there again it is also dependant on the circuit speed where you are shooting from. A 1/50 sec at 50mph will produce the same amount of motion blur as 1/100 sec at 100 mph.
With regard to BBF all you are doing is pressing two buttons instead of one to achieve the same result, and if you have not used BBF before it does take some getting used to, but a lot of people prefer it.
So the best advice I can give is PRACTICE, PRACTICE, PRACTICE, and eventually everything will fall into place.