You need to move only files with the *.db extension, if you want to move databases. And this must be performed, when the node is stopped (the service storagenode must be stopped), and you need to change the option
to the path where is now your database files are located before the start of the service.
No. It just means that your node is restarted too much during attempts of upload something to your node. If these files are older than 48h you can remove them while the node is stopped.