Lets be reasonable here, not everyone is a great rider and they go to the track to get better, to build confidence and to gain skills you dont learn on the street that will benefit in all forms of riding. Not everyone wants to drag knee or be a professional racer. Not everyone has the funds to go to the track, shoot, alot of riders dont even KNOW what going to the track means. (In my area they usually think its the local drag strip!
Then get offended when I laugh...)
That being said, keeping a track to one certain class is not even logical or at all reasonable. If my local track (still being several hours away) only did exp. riders, I'd never go, simply because I would be intimidated and nervous I would get killed by assholes who think they're Rossi.
My thoughts would be keep it open to all riders, designate classes or days as needed for different types of riders, and have specific times and days for specific classes or events. That way everyone gets a chance and they will keep coming back as they get better and better.
Never allow complete novices to ride with intermediates, like you said Zoomie, you get those jerks who really should be in the advanced class but like to look good, and they endanger novices who are trying to learn. If you are trying to learn your line, its not so easy when assholes run by, improperly pass you, buzz you etc and you are too busy trying not to die and not focusing on improving. Yeah tracks try and control this, but it happens.
And imo its freaking awesome to be able to watch those really experienced riders go at it in a class of their own, b/c I can watch that, see how good people can get in person and have something to aspire to.
One thing that really helped me visually was seeing the track marked with the proper line for me to follow. Jennings has those big dots on boxes, and being able to follow those a few laps gave me the physical/visual knowledge to apply what I knew I should be doing. After a few laps I didnt really need them but it was a comfort to have them.
Control riders that are knowledgable, friendly and helpful!! The peeps at Jennings are freaking awesome and I learned so much, but if they hadnt been friendly and approachable, I wouldnt have learned diddly!!
The flag system was awesome, and i think way more eyecatching than lights would be simply because when I get in the zone, movement is more likely to catch my attention than a light, but maybe if its flashing that would help...of course the flag wavers helping you pick up pieces is helpful too!
Everything else mentioned, like outlets, covers, tire and suspension people are all also things it'd be great to always have.
Have those people/vendors offering services be a lil less pricey than your regular shop and they will make a killing on track days because people will be willing to spend that money while they are there, especially if they are getting a great deal. Think Wheeler's up at the Dragon: I was more than willing to wait and pay cash to get work done because I was there, I wanted to see the differences and results and because he charged reasonable fees! Or even bike shows and rally's, I will go to a bike rally an hour away to buy a set of tires because while they are there on site i can pick them up for at least $100 cheaper than buying them on a normal day from my local shops. That kinda thing...