No, because most users have smaller screens, by default program has date and other columns there, and sort button above them so that can't fit there. Then only thing that can go there are view buttons (Setting>General>View editor at the bottom). Besides, that same files panel is for columns layout and there is definitely no space for that there.
Some future window layout will have another optional separate toolbar with buttons.
Use shortcuts.
I have not had an optical drive in a over 10 years, so if I find an external one I can check what can be done.
I don't see why an inactive drive should be visible. I have multi-card reader and Explorer shows 8 empty drives, but I don't see a point in showing something that can't be used. Do you have a usecase?