I set my Library window to be divided like this so the text of a “Group” shows.
When I quit and restart RW my division of that window reverts to narrow. I don’t want that.
The more I use the library as “Window,” the more problems I encounter. Close a project, the library Window stays open. Open another project, another library Window opens on top of the other library Window. It’s more of a mess than a value. Going back to “Sidebar” view and I’ll live with it’s deficiencies.
I agree… it’s very confusing.
There are, unfortunately, some significant limitations to being a plugin within another app. I think you’ve bumped into a few of those here. I can see what I can do, but I know that a few of your irritations fall into the “infeasible” category. 
But, there are two other modes to choose from, perhaps one of those would suit you better. 
Isaiah
Understood. Just pointing out issues I have and I’m trying to find solutions that work for me. I went back to using “Sidebar” mode and all is good now. Might try “Popover” mode too. I have set my icon size to small, and that makes the list more compact so more can be seen at once. Thanks.