Well, the ‘normal’ windows rules apply – half way.
In Windows if you left-mouse-hold & drag you can select a group of files. Not so in Vegas – it selects the timeframe for a loop.
While your suggestion to hold the shift key down and select certainly helps in selecting large groups of tracks and segments, I would have hoped that Vegas would make a mouse-hold-drag selectable (predetermined obviously) as to what function it performs.
Steve