I find with the current path system, it's too curvy/windy, which is a problem if you want to create cattle-pen style queues such as those seen in the smiler. A nice option that I would like to see is to have an option where the curve when doing 180/90 degree turns can be removed. Most cattle pen queues involve having a floor, then placing loads of fences over it to make the queue, whereas in PC the paths are too individual, where there's a full curb with a gap in the middle etc etc.
This links in with this topic - you can create a variety of style of queues, perhaps a more organic one with trees, no fences/curbs etc, but also allows you to create cattle pen queues.
Regarding the curbs, I've personally never seen a queue with curbs like this, it's either just a fence in a cattle pen, or maybe a row of rocks instead of a curb. Obviously this could add more detail into the game, allowing to to select how you want the queue curbs to be.