Good work so far. The UI states that it is a 'work in progress' so I'm going to treat it as such.
I'm not too fussed about the 20 pits thing (although maybe you could line the pits down both sides of the pit lane and leave room down the middle for the cars to drive past), but some of the bumps should be more subtle and the track badly needs replay cams. Some of the tarmac textures (mainly the one behind the start / finish line) could be improved too.
But as a work in progress, it's great, and will definitely be worthy of five stars with these fixes.