There are many ways to expand storage and move to SHR1.
Suggest you talk to Synology Tech Support. They can guide you through the steps.
Consider creating a browser shortcut pointing to https://app.plex.tv/desktop or to the IP address of the NAS, https://nas.ip.address:32400/web. Then you do not need to login to DSM to access Plex Web.
The ability to display/hide the PMS icon in DSM was recently added and confused many people when the icon disappeared. Plex will back out the change in a future PMS update (exact release unknown).
In the meantime: FAQ 34: Control Plex Media Server desktop icon visibility
