I think it could a great thing, and it's opening a large can of worms. We're talking everything from county permits and hiring sound company, and getting liability insurance and dealing with ASCAP and BMI, all the way down to managing a mailing list, hiring security, doing printads, flyers, maybe radio promo, rounding up volunteers and the like. Mucho stuffo.
Now that I've scared you, you may want to take a deep breath and reconsider! But if you are one of those bluegrass NUTS that make our world turn, I'd be glad to talk about the specific questions you ask. It’s a big enough job, it really involves a year-round set of activities. I've not done it myself, but know a fair amount about it, and my hat's off to those who do it, because on top of the work itself, there is the financial commitment and risk. Most festivals take 2-3-4 years before a profit is seen, so the investors have to keep ponying up before they see anything.
Good bluegrass headliners can be hired for $5-10K per day. Good "known" acts get less, and the best of local acts get maybe 1K tops, because they are mostly looking to be included for the good exposure, and just being included. They can also help tremendously with local promotion, as they can be like festival ambassadors. A band or two that does that well would be great to get in your camp. The booking process is always a bit of a dance, but even including a bit of haggling, the process needn't take long if you are ready to commit to spending the $. Agents are not likely to relate to an inexperienced event presenter who's iffy about what he wants. I mean, they'd make suggestions, but as agents, they're likely to not give necessarily the most realistic picture from *your* point of view. They serve event producers, but they *work* for the acts, first and foremost.
The venue should have shade near the stage, a good pickin-friendly parking area, RV space for sure, hookups a la campgrounds if at all possible (not necessary, but a good selling point). Real running water-type bathrooms (showers a big and rare plus) will make a pretty big difference to a fair proportion of people, though as with Merlefest, portojohns are the industry standard. Never skimp on sound (tragic flaw for some festivals), and hire a company that knows **bluegrass** (!!!) not just rock or country.
The acts themselves might really like a festival that is comfortable to be at (though most will have their own portable comforts on their buses). Backstage food of any sort is a nicety, and a way of getting a decent dinner without having to go buy it at the food concessions is a stress reliever for an artist who is just hungry and doesn't want to mix with fans until later. Then if you're just nice and accommodating and pay as per the contract, they'll be happy to play there. Big crowds mean a lot to artists for all the obvious reasons, certainly including record sales (which you can facilitate by providing tables in a shaded, lit-at-night area in a good location).
That gives you a taste of the wacky world of bluegrass festival presenting. Not for the faint of heart, and most definitely a team effort. Building the team is a major factor.
My biggest recommendation to you is that you start your education by attending the IBMA World of Bluegrass convention in Nashville the last week of October. Get information at www.ibma.org. Attending the weekday (business) part is much more important than the weekend (festival) part. A lot of experienced event producers will be there, and some panels and events are geared especially to them. That's where you can learn, and more important, network with others in the business, and they will be the main people you'll learn from.
I think if you have a beautiful location that people would enjoy, that's a great start. If you really think you can deal with all the other pieces of the puzzle, go ahead and jump in. If it weren't for people like that, I have no idea where bluegrass would be today.
Best of luck!