There is a way to do this and I swear it was in the Wiki or the Tuesday tips on Avid2FCP, but I can;t find it so I'll describe it again. It's odd.
Place your playhead at the beginning of the sequence.
Select all with apple a
Drag the selected clips from the timeline to the right hand side of the canvas where a popup window will appear.
Drop the clips on 'Overlay with transition'
This should drop a default one second cross dissolve on every cut. If you have something else as the favourite, then it will drop that instead. If you don't want the audio to crossfade as well, unlink it before dragging the video to the canvas.