As requested by Martin Owens here: http://sourceforge.net/p/inkscape/mailman/message/34734828/ Currently, either possible by multi-difference extension or by duplicating topmost object and repeating, which can be annoying... Combining can easily be chained afterwards or before, if you want a combination. As it's destructive, it would be nice to leave that out of the 'multi' process and let the user decide. Possible to do the same for the remaining two-paths-only operations.
I recently found Martin Owen's brilliant 'On Canvas Alignment' proposal https://www.youtube.com/watch?v=Wk_wf1heHF4 It's a great idea but suffers from some issues, e.g. visual clutter and focus on alignment points rather than lines. I took his idea and did some thinking of my own.
This is an idea that devs are already working on. I use SVG to play al ot with the shapes and location of elements . do you find it useful? give them feedback then and help them :D.