1. Is the secondary wifi device a router? If so, it needs to be configured as a WAP, Google "router as WAP" to find tutorials. Basically won't use wan port, disabling SOHO router type functions.
Allow the Comcast gateway to run the network, it will do just fine. The entire subnet will be a 10.0.0.0 / 24
2. You have a network cable from both the Comcast device and the other wifi device both going to the same switch. It's one or the other. The 8 port switch should not be connected to the Comcast gateway and the other wifi router simultaneously.
3. The thing on top is a patch panel. All your drops go there, then each drop you want to "activate" needs a cable from the patch panel to a switch.
There's technically only 3 drops activate right now, all going to the Soho router, none to the 8 port switch from the looks of it.
Please post model of Soho router (aka secondary wifi device)