You can't expect the slower guy to just stop and let everyone by. The faster person should know how to pass and when to pass. I've seen too many times where some guy wants to pass and as he passes, he pulls a brain fade and goes wide which forces you into the wall. Leader does not equal track owner. Sometimes a guy would pass and then slow down, c'mon whats with that??? This is racing, you should expect a little competitiion or agressiveness. Just because you are the leader does not make you Moses. If you are a better and faster driver, you should be able to pass smoothly and quickly.
Now in regards to longer races, I'm in favor of it so long as we allow 20 car mains. One thing I hate about big races is the wait. It is so long that eventually you forget about why you are there to begin with. So if you eliminate some of the non-sensical classes and double up on the grids then yes longer heats and mains would be fun. But if I have to wait almost 2 hours between runs, then forget it, I have a better chance with lines at Disneyland.