[dnanian]

To answer the last question first, I always format drives journaled. Always.

For the first, I can't think of a single time I've experienced "bit rot" with existing data on any drive that didn't explicitly fail (that is, a quantum bit-flip, as opposed to a sector going bad). So, I do what I recommend in the User's Guide - I maintain multiple backups. It's vanishingly unlikely that the same file is going to go bad due to drive failure on multiple drives - and nearly all my backups are on RAIDed (redundant RAID) drives to boot.