#1, #2: Unsupported - sure, but the behavior is weird.
If multiple selections aren't supported for a given command, then the multi-select should be converted to a single selection first (by dropped all selections / cursors except the "active" one) - not allow random wierd behavior.
I was playing with this option because I thought it would be nice if I could move the cursor around inside the selections (as well as begining / ending of selection). Once you get to the begin/end of a selection it would be nice to be able to do something (like insert, toggle case, etc), without losing the selection.
Multiple cursors isn't very CUA-like either :-)
#5: WRT paste: Yes - nice, though the first thing I tried was pasting with a single cursor, and expecting behavior like vertical block.
I'm kinda surprised that there isn't a "Paste Special" option to toggle between vertical and horizontal.
The "Clipboards" tool window has a horizontal/vertical context menu - but it doesn't change the data format, just the window :-)