Looks 99% good.
You have an orphaned config rule between the forwarding statement and the guest dns rule -- delete that orphaned line:
And for the guest bridge, add eth1.10 so it looks like this:
config device
option type 'bridge'
option name 'br-guest'
list ports 'eth1.10'
Restart and that's it... router is done (with the guest network). You'll repeat the process (later) with the IoT network.
Next, we can work with the switch. We just need to see /etc/config/network and we need to know what ports connect to the router and each of the APs.