I finally found out how to rearrange the icons in the left-side Launcher bar, but I thought it could be done more intuitive because I had to do a web search to find out. Scrolling is reserved to dragging up and down (which is what I thought was for rearranging icons), but if the mouse wheel or up/down/Page Up/Page Down keyboard buttons were used instead (while hovering or focused), that would make more sense, or even add a scrollbar to drag. Currently if I have more icons than fit in the launcher, it's actually more work to drag up and down than to just flip a mouse wheel.
Is this even configurable? I'm trying to learn Ubuntu. Even a way to lock it would be nice. Thanks