I agree with Craig, but I am going to try and do both Ohio and Mosport.
Last year I managed to sneak into the Mid Ohio event by applying for a AHRMA license way early, and then just registering. They never said anything to me. It probably just raises eyebrows if you don't have one or try to apply for both at the same time.
We camped by the Keyhole, which is pretty far from the showers/pits, but they had a shower truck and bathrooms there which were fairly clean and easy to use.
It IS a big event and more high tech (even though they don't use transponders), but it didn't seem too hairy. There are still a lot of slower guys who show up and the grids didn't seem all that larger than, say, the last LWSV race at NHIS. It was one of my first decent, no-break-down events and I got somewhere around 6th or 7th in 350 and 500. I think everyone would do fine...
-Aron