I would like to join this thread. I was used to using the up and down arrows in FCP to jump back or forward to the next or previous edit. In FCP this works very well, no matter which tracks are enabled. In MC7, the topmost active track seems to determine where you will jump to. Also, the little pink hilight is placed on the transition point between clips, and next time you hit play, it will jump back and play to that point and then repeat. I take it this is the “trim mode” that you are referring to. I too would like to defeat this, as I find it very counter productive.
Snapping, and being able to jump to the next or previous edit are important tools in teaching students how to not produce orphan frames in the sequence. I think this is a weak point with Avid, and I would like to work around it if there is a way.