When you export 16:9 footage for a regular tv, it has black bars at the top and bottom...so which safe zone should I follow for the edges of the screen? The 'Action Safe' or the 'Title Safe' margins? The top and bottom are fully visible yes?

I import my 16x9 footage into a new 4x3 project, go to "interpret footage" and change pixel aspect ratio so the footage shows up correctly, not distorted in the preview window. And now I can use the built-in safe zones.

Heresy: I find that with an HDMI connection, both DVD and Blu-Ray projects are pixel perfect and crop nothing from the sides. My older component HD set crops just a bit left and right. Those "safe" zones will soon only apply to analog TVs that are recycle fodder!