Data "pass-through" to physical COM port on the PC

Here: DS 1.2.0: Traces when in FCM Data Mode - #3 by awneil

Yes, I think that is the case.

It was included in the SDKs before M2MStudio, but the easiest way is to ask your Distributor.

No.

One of the major changes in the Target Management “refactoring” was to remove Selima - which TMT Relies upon.

You should still, I think, be able to use TMT with an application built by DS 1.2.0 - but TMT cannot share a comms link with DS 1.2.0.