I find the timeline to be incredibly difficult to "read" for the single reason that you can't easily see how long clips are when they are back to back. The contrast of colour where there is overlapping is not enough. Is there a way to change this?
Based on your question about transitions from landscape to portrait, i'm guessing that you're trying to solve this problem by using two separate video tracks instead of overlapping events on the same track. Am i correct? Are you doing this so that you can see the events without them looking like they are overlapping? If so, you should still be using a single video track. To get a separate "AB" view, click the Expand Track Layers button in the track header. This is the third button down on the left edge and looks like three tiny squares.