Backups, External SSDs & General Maintenance?

BezO

The Artisan
With some recent changes, additions & things generally getting more serious, I need to address some administrative things I've been putting off or doing inconsistently and/or inefficiently. I'm hoping for some suggestions.

1a. I'd like to use Time Machine for backing up and sharing Logic Pro X session files between CPUs, but what would be the most efficient way to do this? The sessions need to be shared between my iMac & Macbook Pro, and I'd like to keep a backup on an SSD and maybe even iCloud, though I hate the idea of my product being out there like that.

1b. Can Time Machine be used on just a single folder? And can it be used to save back ups to multiple locations?

2. Because my main CPU was a Macbook Pro for the past 1.5 - 2 years, I've often disconnected my external SSD containing my samples/content when mobile. With the iMac replacing it as the main CPU, I'm inclined to leave it connected but wonder if this creates extra wear and tear on the drive. It's a Glyph Atom RAID SSD, so powered by the CPU. But I guess constant (dis)connecting creates wear and tear on the input.

3. Do rackable thunderbolt 3 SSDs exist, or are the only rackable solutions 2.5/3.5 drives installed in rackable enclosures? I've used rackable Glyph 7200RPM drives in the past and can't find SSD thunderbolt 3 equivelents.

4a. Specifically for Logic Pro X users, I keep Logic's samples/content on an external drive. My understanding is that 2 CPUs can't share sound libraries. Is this correct? If so, can they be 2 duplicate folders on the same drive?

4b. Related, Apple recently introduced an official way to install/move its sound libraries to an external drive. I had been using Symbolic link to accomplish this prior. Has anyone made the transition from Symbolic link to Apple's official method? Any problems? Does it effect storing sound libraries for 2 CPUs?

Thank you!