If you want (and if you can use it that way) you can download from their site http://www.kdenlive.org/ VirtualBox image.Yes, but performances are going to be extremely bad, aren't they?
I really don't know, that depends on your hardware and what you want edit.I have Squeeze and Kdenlive on IBM R51 laptop CPU=1.6 RAM=1024 but I only edit sometimes small movies from camera. I guess if you have any modern CPU and 2-3gb RAM it would be enough for VB+Kdenlive, but video editing is always CPU and RAM hungry.
-- Bye, Goran Dobosevic Hrvatski: www.dobosevic.com English: www.dobosevic.com/en/ Registered Linux User #503414