I think Neovas are used in japan. At least they were used (Taneguchi used them). D1 UK winer was dusqualified on the otherhand becauzse he used neovas which are illegal in the UK. IIRC at least.
EDIT: Smoke is a setup thing. SOme setups produce little smoke, Chris (.Inc) made a setup once, that made 'huge' amounts of smoke.
The FXR can be competetive on BL1 and SO. LFS GT, n1 and ITEK were running FXRs, no XRRs, out of 8 cars, ITEK was 2nd or 3rd i think (Cropsy and The End) and we were 6th. It looked like we were going to be 5th but in the end a FZR was just faster. The next race is SO Long, the last chance for us. Then we will be just lower. Things should be improved, yes.
How are you going to filter them out? I thought so. The only way would be to have a tag at the server setup where you'd choos if it's a racing server or not.
Real tracks wouldn't be used because of licencing stuff anyway... And even imaginary tracks would hardly get used because the devs want to keep everything in-house. At least that's how i see it.
And don't forget, MAAAAYBE LFS will open up after S3, Scavier said nothing about this, it's a community idea, don't count on it much then.