thats a lot of issues without much detail. I agree there are a bunch of "semantic" ambiguities. Do not confuse the UI with a Library View. Libray Views you can save, UI configuration you can't (or you have very limited options)
1) Question are you trying to do these things on a client machine that has loaded a server's library? If so you shouldn't be.
Are you doing this by right clicking on either the pane bar or from the Tree Item? ... or are you referring to Load/save from the top menu is not the same thing - frankly I don't know what that does
3) you can set presets if you want for the columns shown in playing now
4) split views is a semantic issue --- do not confuse with Library Views which are what you can save or load
5 - you can't to the best of my knowledge, you can just bring up the last "state" if memory serves.
6) the tree can be toggled on or off -- again last "state" will be kept in temp memory
2-7 have I misunderstood? are these feature requests, or are we just feeling a bit entitled today ?