yes you can.
Merge bridges, add appropriate VLAN interfaces, so CPU has access to VLANs and then move your DHCP servers and IP adresse to those VLAN interfaces.What you want to do is doable with one bridge an VLANs.
Running the DNS cache is not your problem. It's not having appropriate firewall rules.Yes it was DNS issue. After disabling DNS, it is working normally.
/interface ethernet switch set unicast-fdb-timeout=300