Yup, the aiming point was relocated during work in progress, and at the same time, a safety survey was carried out regarding heli's touching down on the taxiway. That concluded that taxiway aiming points weren't safe, and for BAA to create an individual landing site wasn't 'commercially viable'.
ATC restrictions are such that you have to use the duty runway, and from a holding point that doesn't produce additional departure vortex restrictions (hence the hover taxi to 08R G1?). ACL have to issue you with a runway slot (via Interflight?) to be accepted into the system as LGW is a fully managed runway. This slot doesn't give you any priority and ATC have to be impartial and treat you as just another customer. Our main purpose is to produce maximum runway utilisation, and no offence, but heli's tend to slow down the operation.
What I tend to do is engineer a departure gap that has been extended by 2nm at most, get the heli on and away with an early turn (they're not restricted to NPR's) and then fire a jet off behind you. I prefer to be rid of you ASAP rather than worrying about you flipping over in the hover.
On that topic, we have no restrictions regarding you hover taxying behind jets or beside the runway, (jet blast/vortex) but are fully aware of the problems involved and safety implications.
Re-reading your post, if you were behind 15 IFR jets, and you were VFR, nothing personal, but 'VFR will not hinder IFR'; then I'm sorry to say that you were the lowest priority.
The bottom line is, and this has nothing to do with ATC, but BAA do not want heli's operating at LGW because they produce no revenue and take up too much runway time.
Hope this helps in some way, but feel free to ask any further questions.
Muppit