I found some ancient software - questions

I've been playing with the idea of buying an old (OLD) Mac just for a stroll down memory lane. Maybe an old PowerBook that could still be useful as a portable typewriter, or an old desktop for running my really old stuff natively. Etc.

My problem has been, I didn't want to mess around with emulators -- I wanted the original hardware too -- but most of the old Macs I find don't have any OS on them at all, and the oldest OS I thought I had was an 8.5 installer, which was PowerPC only. Imagine my surprise when I found a dusty old box of floppies marked "System Software Install Disks 1-13." They appear to be installers for 7.5.2. I think I used them with my old PB 190, may it Rest In Peace.

Questions:

1. Is 7.5.2 a full version, or just an update?

2. Does13 sound like the correct number of install disks? Am I missing anything? There's also a DiskTools disk, and something called "NDD Startup Disk" which is empty.

3. I see a file called "Minimal 5300/2300/190 Enabler" on disk 1, so I know the software would work on those models. What other old Macs will run 7.5.2?

4. Is there any harm in copying all these old floppies to CD or hard disk for safeseeking, then re-copying onto fresh floppies as needed?

Thanks for listening to my dumb questions. It's been 20 years since I had to worry about this stuff.