> The author mentioned copying the Time Machine drive. I have never been able to successfully do that. Last time I tried I quit after 3 days. As I understand it, only Finder can copy a Time Machine drive. Terrible experience.

rsync -av $SOURCE $DEST has never let me down. Copy or delete on Time Machine files using Finder never worked for me.

> Problem is I don’t know how to prevent it. It’s been suggested that SSDs are potentially less susceptible to bit rot, so maybe switching to one of those is a wise plan. But I don’t know.

OpenZFS with two drives should protect you from bit rot. ZFS almost became the Mac file system in Snow Leopard.