and I think they also still employ Flight Test Observers (FTOs), a position that has historically been a springboard to FTE status. The FTOs have typically been engineers and trials officers, whose work involves occasional requirements to fly. Airborne trials photographers are also in the FTO cadre.
I would say that unless things have changed a lot that the aircrew role at QQ is pretty much separate and complementary to the job role.
Trials Officers at Boscombe Down are what most of the world would call FTEs. Unsurprisingly, the majority of them are professionally qualified engineers, although there are a few exceptions - I can recall a few current or retired RAF Navigators when I was there, and one physicist.
Photographers, well they're photographers.
The FTO role is inevitably compatible with both of the above jobs. But, for example if you're on a single seat fighter programme, then you may well be an FTE, but you're unlikely to have reason to fly as an FTO.
The same would be true many other places - BAeS at Warton for example employs a lot of FTEs, but very few of them fly on trials.
If you want to be an FTE doing a lot of flying as part of your job, transport or training aeroplanes are probably the best place to be, followed by helicopters, and least of all fighters.
UAVs are interesting - they also need FTEs, typically with an excellent understanding of the eventual role of the UAV (for example I work mainly in earth sciences research flying, where we do a lot of UAV work, but most of our operators and testers come from an earth sciences professional background - possibly via airborne science in manned aircraft). Some of those may get involved in pilot-in-the-loop work, but fairly inevitably there's no flight deck to progress into. That said, I've met a few earth scientists who progressed from the lab to the flight deck as well - research pilots are not the same as test pilots, but the skill sets have a lot in common.
G