If you take nothing else anyway from all this just be aware of the fact that you need both archival backups and incremental backups to be truly protected especially when talking about digital images.
This can be accomplihed in a number of different ways and the actual procedures are entirely up to you.
I thought it was a bad idea to have Time Machine backup your AP3 library when all (my) images a "managed"?
I use TM but exclude my library.
That has long been fixed. Time Machine works well with Aperture and iPhoto libraries, even managed libraries. They will be backed up incrementally. But I usually quit Aperture before starting a Time Machine backup, just in case.