More seriously... Great idea for a thread, Jerry. Most of my experience for special access is for press, but the principle can also apply. Some other random thoughts, to add to the good ones so far.
The Shuttleworth Collection do flightline walks for the photo groups - I'm rusty on the details, but it's normally an escorted small group, maybe one of the OW crew can chime in here. Duxford used to do the same for press, and it's often a case of trying to heard cats as the various photographers try to get 'the shot' and in each others' way. I think it's been stopped / restricted as they were annoying the (paid-for) flightline walk crowd given they were in the FW people's photos.
You'll need a clear, signed agreement, and be prepared to sanction people who overstep the boundaries of the extras offered. Almost all the photographers are going to be reasonable people, but in my experience there's often one or two who take what's given and demand more. Sometimes putting themselves and others at risk.
Duxford used to do a press photographers pit on the far side of the runway, back in the late 80s. There was a liability disclaimer, and given that it was in the area near where there were a couple of accidents years later, there are issues. But it can deal with the sun direction issue, and careful planning can moderate risks.
The Classic Fighter show at Omaka had a truckbed on the show side of a big screen for press in 2007 (and I think 09) for the press, and this gave the photographers great access (on the corner of the flightline) and also, because of the screen, they weren't themselves blocking the crowd view; the screen was.
Limit the numbers so it doesn't become a zoo.
Perhaps first come first served, or tickets on the day, and for future years, those that can demonstrate support of the show with published photos or material supplied to the show for the show's use. - Roughly what Duxford do/did for press (acknowledging the different criteria).
Stuff like night, dusk, covers off, stands or crane shots are all great. Make sure it's clear how to get on these specials, manage the numbers and be clear that there are time limits. There are some 'photographers' who take an age to get a shot because they aren't as good as they think they are; and everyone else has to wait up or wait for - not good in changing light or a short engine run.
Night engine runs for instance. Have it well stewarded, clear no trespass limits. I've seen pro- as well as amateur photographers prepared to walk into props jet intakes while trying to get 'the shot'.
Recriators is a split - some love it, some hate; but I like your thinking and it'll be good publicity for your show. Just don't bring down the visiting 172 with the flare.
HTH.