Hi there,
SO I have the same setup, but using PFsense in Router 1 spot and a WAP for WiFi
The DHCP on the router is Small scope only 20 IP range, WAP gateway Address is the PFSense gateway (default) I forward DNS requests also outside of my WAN ip. I have a third interface for DMZ and Testing off of my LAN network. The WAP is handing out IP’s for the wireless clients and the scope is contiguous from the Gateway. ALSO subnet mask is 255.255.0.0 so I can see the other subnets 
HTH
GL 
PJ 
Everything is based on Rules, SO. DHCP, DNS, Static IP’s, Firewall and Routing.