O.P. hit on some valid issues and I agree the smaller events lend themselves to an ideal warbird airshow, but the organizers and participants have to execute. The Thunder on the Lakeshore/Manitowoc Wisconsin airshow is a great example of a well organized (mostly warbird) show covering all the bases: Small, accessible venue (always close to food/beverage/potty), big sponsors so cheap admission ($6.00!) for Herkemer and company (sorry O.P.), access to the aircraft but an enthusiastic cadre of flightline volunteers (Rhonda and Co. were awesome!) provided more than adequate security to counter Herkemer's delinquents; competent air boss, waivered airspace with a reasonable FAA rep, and a wide variety of flying and static aircraft from R/C and model rockets, flip flops, warbirds, military, USAF demo jets/Heritage Flight--a schedule that didn't drag on and go alllll day long. The organizers really showed great hospitality to the airshow participants and it had that feel of a bunch of buddies and enthusiasts really coming together as a unit to make the event work, fly and display (almost everyone did) their craft and gather later for "debriefing" over adult beverages. This show is gathering momentum fast and drawing more varied aircraft (Chuck Greenhill brought his Grumman Duck--cool!), more warbirds every year and I can't wait to go next year. Another great element is the fly-in side of it where anyone can fly in for breakfast in the morning and have better than half the day to stroll the flightline, take pictures, chat with pilots/owners and crew chiefs before the airspace closes in the afternoon for the show. From my perspective as a warbird nut and participant, this show struck an ideal balance and was done very well-- and no jet truck or drunk farmer-in-the-cub routines! The Waukegan Air Show north of Chicago is Sept 9th and is a small, easily accessible event with a number of interesting warbirds attending/flying. Might be worth a look if you don't live too far away.
Anyway, O.P.'s got a point about the Feds and perhaps that's luck of the draw, but I'm convinced crowd problems can be overcome with good flightline organization and (reasonable) security planning. It's on the owners to ask the organizers for help with any specific security needs on their aircraft, like keeping folks from sitting under a wing that drips fuel.
Having said that, I've been to a smaller show that made the fly-in folks (warbirds and general aviation) feel like they were an imposition--parked in a roped off area on the far side of the ramp--it was strictly about Blues or T-Birds at show center and everything else was an afterthought. Too bad since the airport is ideally compact, and there are tons of warbirds a short flight away that could really add interest to the show.
http://www.manitowocairshow.com/