You shouldn't just automount external drives. That's a recipe for trouble.
What's wrong with manually mounting them? Pretty sure the desktop environments also require you to push a button (eg, select the drive in file manager) to mount external USB drives.
I can whole-heartedly recommend the Aqara Power Plugs. They are Zigbee, has energy monitoring, works flawlessly with Home Assistant via ZHA and come in US/EU/UK formats. I have about 10 of these and I have not been disappointed in the 5 years I have had them.
Windows might have locked the drive, making it read-only (hybrid power off stuff) or you might just need to mount it with rw permissions.
How did you mount it?
I sometimes see it in the CLI when running apt update/upgrade. I've just tricked my mind to look past it.
I assume that your inbox size counts against the cloud storage they provide?
Seems it only handles "archived" games. So they need to be archived in a single .zip/rar/gzip/tar file.
Would it be able to handle .ISO files?
Answer: Yes. Found it in their documentation.
I had an experience like that. The droplet was used as a seedbox for Linux ISO torrents (truth, not a cover) and after a couple of months they contacted me, saying they where seeing abnormal activity to and from the droplet and I should investigate and take action within a week, else they would turn the droplet off.
After I explained it to them they replied that using a droplet as a seedbox was not allowed, poinnted to the relevant part of their TOS and I agreed to shut it down.
What the OP is experiencing is a poor way of doing business for them.
PATH is a shell variable that defines where stuff can be executed from without writing their absolute path.
So the export PATH command just adds the scale stuff to the path.
They tend to use different theming engines each major version, so I don't believe they are.
Gimp is likely still using gtk2, which means you need a theme that supports gtk2. That's probably old and un-maintained, since gtk2 has been End-Of-Life for a while now. gimp 3.0 is approaching though.
I don't see any errors, just warnings. And GTK is very verbose about warnings...
If that's the case, then you should answer the OP with how it's set up. OP is specifically asking how to do it with random drives other people hands them, not trusted drives always connected.
Auto mounting random USB sticks has never been wise. No telling what random malware they contain.