If I do decide to use the Crop effect, do I need to render a preview before I export the sequences? Is there a way to export/render many sequences at once?

Overscan is indeed a leftover from good old 'analog times' - it was needed because the analog circuitry could not be calibrated for the picture to fill the screen, due to electronic component tolerance. With the new fixed pixel digital displays this could be dropped, but because compatibility with older TV sets has to be maintained, overscan is still in use.

However, different manufacturers approach the issue differently, and the general tendency is to reduce overscan. While some old CRT sets have manufacturer recommended overscan of as high as 10%, today some LCDs go as low as 5% and I've even seen 3%.

1. No, there is no need to render.
2. Not that I know of. If you have to do this on 80 hours of footage, you're going to have some serious time management issues!

A much better option for cropping would be to use a program capable of batch encoding, like ProCoder. Procoder can also be set to improve the footage if needed.

I'm starting to see advantages as a FCP user I took for granted.

I have two PCs so while one is capturing I can edit ones that have been already captured and copied to an external hard drive. But yes I'd have to have that ability to make it worth my while.

thx

There is no theoretical need for overscan/underscan on LCDs, but I think some margin is still being cut for exactly this reason - there ARE artifacts in both digital and analog video.