So, we got the default look now - with categories. How about option where people who add locations can choose what marker-icon they want and all marker-icons to be listed into main map without categories? this way categories wouldn't need to be listed and there will be more icons to choose from, so the category scrolling will be avoided.

I'm sure you thought about this Dan, but I guess its a bit complicated just came on my mind, I hope this will be done.