What if "noob" is being described as follows.
A "noob" is a person whom has not (or rarerly) raced in a RD league or event.
You could prioritize them to the people who already have some experience. I think thats ok, since we are talking about a noob league. Those who have applied to RDTCC are expected to be experienced. This is what is requested in the info threat. Selection will be done on clean driving, and being reliable in showing up. With 40+ applications, its not a surprise that those who have no experience are not selected. So in a way, the noob league could supplement the RDTCC (and other leagues), and really be "a different level".
In regards to the filled grid, I like it. I like having a lot of cars around, cause that makes good practice. If it's not desired that 24 racers are on the grid, why not set a maximum of 20 or 15 drivers. If there are 30 applicants, divide the league in 2 events (US and EUR time, same days). Since races can be identical, setting the 2nd one up shouldnt be much more work.
Just trying to say that there are options in limiting the nr of racers.
I do think that a little flexibilitie in racing rules could be applied (although I dont think its needed, just be polite, try to do your best, and give position back if takeover was inappropriate and there won't be a problem), but I don't think the requirement to showup when signedup rule needs to be adjusted. IF you sign up, SHOW up. Think thats only fair.
In regards to cars.
If you select the leon euro, or wtcc class, there are choices in the cars. A BMW drives totally different then the Seat, so will be a different experience. I don't think overpowering is a wise thing. If this will be a succes, perhaps a GT newbie league could be the next thing to investigate, but for now I think it's best to keep it as simple as possible. But like above with the mini, I would signup with GT's also