1. To eliminate multicast flooding, hang two switches off the RG. Put all STB and DVR units on one switch, and all other computer-related equipment (basically everything else) on the other switch. Multicast flooding will be limited by the RG to only the switch that has the STBs/DVR on it.

2. Yes, the DVR can be on the same switch as the STBs, it doesn't need to be directly into the RG.

3 & 4. Keep those pieces of equipment on the "computer equipment" switch so that multicast won't reach them.

5. Keep the NAS on the computer equipment switch.

6. Hang that POE switch off the computer equipment switch. If you put this switch on the RG, that means that camera video traffic will flow through the POE switch, then through the RG, then through the computer equipment switch, and then to one of your computers where you are viewing the camera. The RG doesn't do well with high amounts of camera/video traffic like this, so attaching the POE switch to the computer equipment switch eliminates having the camera traffic flow through the RG.