It would require a format change? What device would accept that as an input? It would take an entire spec change for an interface that is past it's prime and into legacy territory.
So your gone and a drive fails. What happens?
Is your fiance going to be able to figure out what to do?
Are you planning on having automated backups?
What if there is some other software issue?
I'd go with something simple like a NAS...
With the extremely limited learning capabilities on the MC remotes (I think one or two could learn?), I dont think is going to work well at all.
There are plenty of solutions out there to do what you want, all are more than $20.