The most important thing to realize about a Mikrotik is that it is not a switch. It does not have a concept of a tagged and untagged or a trunk port or even a PVID. Each VLAN and physical interface in a MikroTik is treated as it's own separate routed interface. Now you can duplicate some of the functionality with a bridge, but then everything is being done in software and you will run into performance issues depending on what you are expecting. You can also play around with the switch chip to see what you can accomplish. I've never used that portion so I can't really speak on how to configure it.
So can a port take in both tagged and untagged traffic, the simple answer is yes if they are intended to be for separate routed networks. If you intend it to be part of the same network then, no. A bridge of VLANs cannot contain the physical port they are associated with. It can be a different physical interface, (that is how you make an "untagged" port) but it cannot be the same interface.