3) I seem to only really get 4 live streams at a time. Them I have 4 off screen.
Where we need some Meraki assistance. Only a HD signal is output from the camera. We really could use a slightly lower resolution from the cams. The RPI will overload and crash if you try to put 9 cams per screen.
I do have all the cameras in 1080p standard mode with no audio. I will try a computer with a GPU game card also. I have setup a few RPI's to pull a video stream. I like them because they are small cheap and fast. Dropping the camera to 720P does seem to help performance....but then my cameras are recording with the same quality.
With cameras from Ubiquity and many others can output a few stream levels.