I believe Wildflower registration is 12:00 am on Dec 1 (midnight). The races are usually the last weekend in April.
You are right that everyone camps. Some people, like Eric and me, are lazy and rent an RV. There are public restrooms and showers though, and even the RVers use those (saves water).
No "real" food available that I know of. I mean, there is a little store and food stand that serves hotdogs and the like. Most people bring their own. There are fire pits where you can grill stuff. Some of the camp sites have electric hookups, but those go fast.
The Olympic distance bike course isn't terrible. Only one really icky hill, with some good rollers in there. The Long Course bike course is terrible. Or so I hear. I'm too chicken to ride it.
I've heard from people who know such things, that the Oly course is about equal in difficulty as a regular 1/2 IM course elsewhere. Partly because of the heat and partly because of the terrain. Compared to other Oly courses I've done, I can say it is more challenging.
Unless you're really interested in doing the mountain bike sprint, one thing you might consider would be to join a relay team for the Oly distance.
I enjoyed doing the race two years ago. My ONLY complaint was that the start the women so late, and don't stagger the start times like other races. Vineman, for example, sets the start times by age groups based on a random drawing. So, rather than having waves start in age-group order, it's completely random... you could have 50 year old women starting 5 minutes after the 20 year old men. And they'll be followed by the 36 year old women. At WF, the older women start last, and many get DQed because the don't make the cut-off time. Not to mention, they're out there during the hottest part of the day.
But, that said, I'd do the race again. It's like a party for triathletes!