NexcloudPi crashes a couple of times week, Your data directory is invalid

Not a good idea, rather use [this howto] to mount a drive permanently (Mounting an external drive using UUID and fstab | Linux admin junior)

Power save, could slow things down, but should just power back on when uploading files.

To check if and where drives are mounted I use:

sudo df -hT

In Linux to mount a drive one uses

sudo mount /dev/sda1 /media/drivename

But you enabled automount so should not need to manually mount unless you add more drives to your system.