Regarding first question. Click on the "Editing" menu, then click on "Clipboard edit." This works just like the clipboard. You first outline what you want to move, then do a ctrl-x to copy to the clipboard and delete what is outlined. You then move it to where you want. Ctrl-C does a copy and leaves the area you outlined in the same position. This is a great tool.
Regarding the second question, I'll let someone who is more familiar with modeling answer that one.
Addendum
I've never tried moving or copying multi-layer areas. Seems it should work. You probably would need to go to the top layer and then outline it. However, if not, you will probably have to move one layer at a time.
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