Can you edit your post and number the items?
That makes it easier to refer to them.
Half your issues are probably already fixed in V5.99. Circles and rectangles can be dragged and resized in both the Symbol editor and Footprint editor.
Selection has also already changed, by holding the [Shift] key and [LMB] you can toggle selection of individual items.
This may be related to a bug I experience too. See:
My current PC is a (probably first gen?) i7-860 and loading the libraries takes around 30s in KiCad V5.1.8, and about 5s in KiCad V5.99.
I never bothered to make a bug report for this.
Why do you find library management such a disaster?
It is a 2 step process. First you have to add libraries you want to use to the library table with: " … / Preferences / Manage Symbol Libraries and after that you can simply right click on a symbol, copy it and paste it in another library. Maybe you are having some difficulty because KiCad’s default libraries are read-only. Which is a good thing.
Writing “it is a disaster” does not help in any way. What are your issues with the library management, and do you have any suggestions in how it can be improved? Maybe you’re just overlooking something simple.
I agree with cedric here. New users sometimes find long standing bugs because they push on buttons in a weird order, or try do do unusual things. My experience is that if a bug is reproducible and reported properly, it often gets fixed quickly.