I was determined not to return to this thread with bad news,
I can report that I have had success. Praise be you guys, you lot are genii in my mind!
I would say I am now conversant in installing many different distributions of linux.
I gave up on debian 11.2 as the repositories didn't have the latest QTPlasmaC in them. It did however install perfectly and is prob my preferred interface.
I gave up on the recommended install of linux 2.8.2- buster and upgrading that to 2.9 and then upgrading linuxCNC. it gets a host of python3 dependency issues which I couldn't resolve and the network manager didn't seem reliable.
Snowgoers' mint image worked a charm. No such issues as with the others. It simply worked as instructed. May be this should be promoted to the official QTPlasmaC document?
I am now on the latest QTPlasmaC and have uploaded (albeit shoddy) a video showing the THC working. Much fine tuning to be done but you can see that it ramps up about 5-10mm successfully at a FR of 2500.
Thanks again folks. Much learning has been done and even though I must be at least 30hrs into learning how to get up to date I am thrilled to have it finally working!!
THC working