I just read the thing about the start-lag and something came to my mind: Sometimes, one person on a server is afk, several people join, the start the race, and because the person wasn't pitting, he/she is in the starting grid, maybe ruining the start of other people and/or the rest of the race, because he/she stands anywhere near the start on the track.
So my recommedation would be, that people, who hadn't touched their controls for x seconds wouldn't be included in the starting grid.
I don't now if this post would be better in the Improvment-Suggestions-Fourm, but it just came to my mind reading the posts.