I just wanted to shed a little light on some of the queries thrown up on here.
All military FJs have Mode 3 transponders so they will show up on TCAS. The Hawk T2 actually has TCAS as well and will receive the same warnings you guys do with TAs and RAs.
Military guys will not routinely turn off their IFF at any stage during UK training. A Typhoon intercepting an airliner almost certainly would!
AWACs won't really be able to give you a BS or TS since they are there to provide tactical control not a RADAR service. If the jets were to want a service to get back to base IMC, for instance, they would contact Scot Mil and the base in question. If they (AWACs) are operating in UK airspace then they will be familiar with UK rules regardless of country of origin.
The ejector seat limit mentioned earlier is not entirely accurate. A mean wind speed of 35 knots (or gusting 40) would stop the guys flying over the area for training. Operations are something else entirely.
As for flying through the area well that's your call really. Just be aware that there will be guys flying around at various heights and speeds working pretty hard. They will not all be from UK Armed Forces. If you could plan your flight to be outside their normal operating times then that's what I would do. Maybe contact the originator of the NOTAM for more information.
As for "dog-fighting" in the middle of advisory airways, there's nothing to stop them (VMC)! I can assure you that they are briefed and usually avoided but in the same way that the OP of this thread is perfectly at liberty to fly through the NOTAM, the FJs are perfectly at liberty to "dog-fight" in W3D.
BV