If you decide to start using a more advanced VLAN setup, you actually have VLAN 1 and 2 already in OpenWRT as standard so you are already using VLAN at a minimum level!
But VLAN1 and 2 are so integrated and common so everyone forget about them.
My advise is to draw a map or sketch over the VLAN setup and what goes where and what are allowed to talk to each other. I recommend doing this before jumping into making configs on all the devices.
Thanks everyone for the input.
Turns out I had two Dell WD19 docking stations on my network. A google search reveals they are known to cause the broadcast storm issue. One was removed, and the other was unplugged from ethernet.
I invested in some trendnet managed switches and setup multiple VLANs to segment my network. Also setup a guest wifi network for my IoT devices.
Haven't had any issues since. 
Glad things are working better now. I am not surprised to hear about the docking hubs... It is actually one of the first things I suggest in terms of potential culprits for frequent network outage events.
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