i haven't been for a few years, but personally i prefer it to le mans (sorry, guys
). it's a smaller event as you say, a lot less "glamour" and a lot more about the racing though there is a decent amount of beer too
. there is no lighting on the infield, but walking around the circuit is totally magical for that very reason. if seeing sunrise at dunlop is the essential le mans experience, i would say sunset sat at the top of eau rouge is the spa one.
i can't advise on parking or the camping though iirc the only option is the local paid parking in various backyards or if you turn left at the hotel/restaurant before the roundabout at the top of la source, and i'm sure the grandstands were free. if you're literally just going for the race i'd not bother with a campsite to be honest unless you're really planning to sleep. take a decent torch, and try and cater for yourself rather than rely on circuit catering. it's a huge ball ache now with having to buy tokens to redeem at burger and chip vans.
the paddock pass is helpful, imo a lot of the atmosphere is there where the new and old pits are rather than in the spectator area behind the old start/finish line.
so er, yeah, no real practical information but hopefully someone will be along soon with some more recent ideas! the event website is righteously crap, you're totally right :/