Hi, I read your experiences, at least parts of it. And it seems that the “Virtual box Limitations and Peculiarities”
that you describe are not as big as you think.
Virtual box does not support copy and paste between the Linux and Windows environments.
Unidirectional copy and paste does work for me. That is I can copy, for instance, chunks of text from applications in the Linux host and paste them into applications in the VBox’ed Windows. I am not sure, how, or if at all, you can do it the other way round too.
When you click the mouse in the Windows screen, the system captures the mouse in Windows and it will not move outside of the Windows screen. To use the mouse outside, you need to press a key to un-capture it.
Take a look at the ‘Machine’ menu, there is an entry called “Disable-”/“Enable Mouse Integration”. At least it works for me.