feature suggestion - "Slip-lock" in the timeline for Multicam editing

Just finishing up my first Kdenlive project under Ubuntu 10.10, version 0.7.8, it's a great piece of software.

I've just edited a 2 hour stage project shot with three cameras and I thought this might be a useful feature. Basically I put the three camera angles on different tracks, synced them to a common audio track, and then chopped out footage to cut between them.

How ever sometimes when I'd try to trim the head or tail of a clip in the timeline using the selection tool I'd miss the clip edge and drag the shot forwards or back, and then either undo and try trimming again or try to re-sync the clip to the audio.

I wondered would it be possible to set up a slip lock button for each timeline track or the timeline as a whole? The lock would stop the clips sliding on the timeline when you click and drag, but still allow trimming. I think this would be a useful option for any video that is cut to a fixed soundtrack (music videos as well as multicamera projects).

An alternative would be to separate the trim mode from the selection tool.

Other features it would be great to see are live video scrubbing when trimming clips in the timeline, preview rendered effects, and proper ripple enabled insert extract editing, but I realise these are extremely complex to implement.