Thanks Flappie, I have a few developments to report:
I disabled Tacview in DCS options, ran a short mission, game crashed, checked the log and it says Tacview was still running.
I disabled Tacview in DCS modules (required a restart, Tacview is still there, but greyed out), ran a mission, crashed, checked the log and Tacview is still running. See attached log.
I will try to remove Tacview from DCS manually and report back.
dcs.log