No.
Plex Dash is a mobile app for monitoring & control of your Plex Media Server. A Plex Pass is required. See Two Delicious New Apps from Plex Labs.
Plex Dashboard → Now Playing is available to all users. Other parts of the dashboard require a Plex Pass. See Server Status & Dashboard.
If you do not transcode video then you do not need hardware accelerated video transcoding.
You will most likely need this if you want to stream remotely, especially if you’ve limited uplink bandwidth or the remote client has limited download speed.
Not supported if running Plex Media Server directly on the Synology.
This is possible if running Plex Media Server in a Docker container on the Synology.
See FAQ #28. Using Docker for HW transcode & Tone Mapping - How To
