Most commercial pilots try and blot the tenerife accident out of heads due to it being done to death in CRM courses. Tenerife was the trigger for the whole subject of human factors and crew interaction. The RT side of things came of the back of that over the years. Quite a few of the Brit practises date back to before that. In quite a few cases the pilots that got killed have been forgotten about but the "good practise" which was the fall out of the accident continues.
what next is correct.
The only time you should use takeoff in relation to aircraft is
a) during PPL instruction ground briefs until they can get there head round they shouldn't use it.
b) when reading back a departure clearance
At work I have done getting on for 100 sectors in the last month I used the word "takeoff" twice and both of them were in a debrief and used in the context of "takeoff roll" which for some would be bad practise. I might add as a Captain I don't generally do the RT on the ground and if the FO was that busy they couldn't take a departure clearance we wouldn't be accepting it anyway. But to be honest this is hyperthetical because I would have refused the line up clearance if I didn't think we would be ready to go when so cleared.
To be fair its not the fault that PPL's use it incorrectly. Instructors are the same and won't get the habit beaten out of them until they start flying in a commercial enviroment. I know Captain's that have been MOR'd and had to visit the Chief Pilot because of poor RT at Manchester airport by thier FO. It wasn't just using take off I might add. MAN is quite strict about taxi clearance readbacks, hold short instructions and conditional clearances the condition being read back first.
Sorry you posted while I was wirting I will leave it anyway because it might install a good practise into some PPL readers.