Totally fine to have KDE set up aesthetically as you please.

They like how gnome looks, not as much how it works.

Personally I avoid external enclosures for data - they can be finicky in many scenarios.

Are you looking to only have one machine, or is it an option to keep the one you have as well? You could put the more intensive stuff on the new machine, and keep the existing as the data store (and maybe lightweight service stuff, like DNS or homepage or whatever).