Take a look around the forums, I believe sideways did a tutorial about installing on a USB stick. Not sure if it's easy or not, though it is very easy to put the liveCD on a USB--I use Unetbootin.
As for KDE, I don't use it so can't answer the question, but a review of SuSE 11.1 said it was quite good---here, I only see people writing about it whe they have problems, so judging from that extremely subjective viewpoint, I'd say, probably better in SuSE. (Hopefully, it's clear I'm joking here. I have no idea, because I only know of SuSE's from that one review and only know of Fedora's from people who post with issues here.)
is the USB howto I mentioned.