Re: Difference btw randori and jiyu waza
More general statements below... Please feel free to correct! More my own interpretation, but seems to fit in with what others are saying. Like Peter said, I think there's plenty of overlap potential!
Jiyuwaza (freestyle techniques) Attacking and throwing is controlled with the emphasis on flowing techniques, and uke is usually compliant. Despite being 'freestyle' we sometimes do jiyuwaza with some sort of limit, i.e. limited types of attack, or in some cases, limited variations of just one technique!
Randori (literally - taking/grasping chaos) Where uke attacks however they like (within reason) and is trying to overwhelm nage/tori/sh'te, with varying levels of resistance depending on how it is taught in a particular school. This obviously is much harder training, that has more potential for becoming a little scrappy! (and people pull better faces in randori!)