I understand where your coming from, but it still seems to me like you are worrying too much about something that "could" happen. I would be willing to bet you there'd be at least 5 other guys there that are worse at driving on a track then you (my self included). Honestly, even if someone is super fast on the track and runs around degrading everyone how slow they are, hes still just driving an RC car. Its not like hes driving an F1 car making millions and signing autographs etc etc. If by chance there is a guy there like that, trust me I would be more than happy to let him/her know how much of a D-bag they are being.

The fact that you are a musician could explain the feelings of what essentially is "stage fright". Just remember this, being perfect and performing well for a crowd of spectators in your chosen profession is one thing, and I can admire you for wanting to get it right. But these are RC cars, a hobby, they should be fun and provide a sense of relief and relaxation. So what if a guy is better at it than you, its just a hobby.
I used to run in to the same type of circumstances playing paintball. I played for years and was an above average player (at least I like to think so) I had decent equipment Angels, Rev-Is, Custom halfblock cockers, things like that. Almost everytime I went youd have a few guys that were always calling someone a "noob" because they didnt have the fancy smancy ulltra high end marker of OMGWTFBBQDOOM. The new guy would be asking questions about how to play, where he should go, what he/she should do in certain situations and have a genuine willingness to learn the game. By days end the "new guy" would be getting picked on the pickup games before these so called "pros". I guess what I am saying is this. If you want to learn how to do something and you have the tools to do it, its totally up to you to do the work. Whats that saying and im probably gettin it wrong here. Its better to have tried and failed, than to have never tried at all.
They do have 4 tracks to run on for varying degrees of skill lvls, a competition offroad track, an Oval/figure 8 track, an extreme track, and a flat road course track. Its the perfect place to learn to run on a race track. You could start on the oval and get used to it, once you feel comfortable just jump over to the flat road course and practice turning left and right. Once ya felt a little more comfortable you could get on the extreme track and pactice jump approach and landings. Then you could hit the Off road competition style track and put everything together.
They might be willing to let ya come up during the week and get track time, all ya gotta do is ask. They've always been friendly to me when I was around, so I am sure they'd try and accomodate you.
Its almost garunteed(sp?) to be a good time, I hope to see you there man. If you do decide to show up, lemme know via PM so I can look out for ya.
EDIT: Where exactly in Indiana do you live? I know of a 1/8 scale track that you could run at almost anytime without worrying about anyone watching you. Its about 1 hr south of Indy though.