Ports ether1, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 are all bridged together (in br-wan). Bridge is something like a switch. Mikrotik’s WAN address is bound to bridge interface (more about bridge personalities), which means all of these ports have to be used for connecting devices with public IP addresses directly to WAN.
Since those ports are bridged/switched, none of /ip firewall settings apply. Hence no NAT, no firewall protection, no mangling (e.g. directing DNS queries towards internal servers).
I’m not sure I follow the problem description above. Perhaps the answer to the first question sheds some light on why router performs in certain way. If not, rephrase the question (perhaps giving a bit more context would help).