Regarding DHCP I’ld run e.g. tcpdump -i wlan1 in a second terminal while trying to connect. The output will tell you, if udhcpd gets a request, answers it and a lot more. Just tried with udhcpd -f /tmp/xx.conf (wlan0 in my config) and got a lot of logs like 10.10.0.6 belongs to someone... due to another DHCP server on my network.
The interface for external traffic should be in the output of e.g. ip route get 8.8.8.8.