I applaud your idea and your effort, but at the same time, I really believe this is going to be a fruitless effort on your part.
To borrow a phrase from our environmentalist friends, "Think globally, act locally."
The unfortunate reality to your endeavor is that so many people have been scammed by undertakings similar to you, and not just R/C related. Certainly you've heard of folks faking cancer, or claiming their (child, spouse, family member) is suffering some illness or disability, setting up a fund to collect donations for medical treatment and the like then running with the money.
There are simply too many unknowns, both about you personally and about your undertaking, that I simply am not comfortable donating money to your cause. Your web site has the look of being sanctioned by ROAR, but is that true? Have you established any relationships with ROAR? Have you considered working with one of the R/C magazines or manufacturers to both spread the word and lend credibility to your effort?
Essentially, you're asking folks to simply give you money on the premise that you will fund the construction of more tracks to encourage racing, right? Where's the control? Who's ultimately responsible for accounting for the funds raised and insuring they are spent as promised? What's your timeline? How are we sure you won't skip town with the money?
About three or so years ago, a young man here in Cincinnati convinced the Mayor and City Council to GIVE him close to $1 million dollars to renovate an old theater in a run-down part of town as part of a community beautification initiative. Know where he is now? Getting gang-raped by the "sisters" in the Lucasville State Penitinary! The man invested ZERO DOLLARS into the project, spent the money on trips to Austrailia, trying to promote some no-name rapper, shoes, clothes...you get the picture.
So, while you may feel the reactions you are receiving to be childish, the point is, you are highly unlikely to get any donations from folks that call this their "R/C Home." Not unless you add an incredible amount of credibility to the effort.
My advice is to start locally in your area, build trust and faith in your endeavor and then branch out. Until then, unfortunately, you're spending money on hosting and domain fees for nothing (or at least very little.)
I wish you luck, but I think regrouping and thinking it through with the end in mind is the better way to go here.