Can someone please explain to me how a slot race works? I understand that there are so many slots available and that you pay for a slot. Do you get to choose a specific slot, or is that deteremined another way?

The slot owning list is not the draw order. Its drawn like any other race. 

My personal experince is you pay half your entry the host ghosts and the race never happens and you never see your money again. 

If you are buying into a slot race for the first time I would recommend a long standing well respected producer and research them. Even rent a slot from a know sucesfull race.