Lastly, professional ATCOs (I don't know about AFISOs) have their R/T procedure regularly checked
FISOs (Airfield & ACC) are subject to competency checks by SRG and this includes R/T standards.
The vast majority of TREs/LTCs do.
True - but there's no recurrent requirement stipulated by any licening authority applying to pilots, commercial or private. This is one of the reasons that the UK's SRG has over the last 12 months, been randomly sampling pilot R/T standards at a number of UK ATC units including airfields/airports and ACCs.
In the UK, NATS is also adopting a more proactive approach to poor flight crew R/T standards (having already instigated a mandatory sampling process for all its ATCOs).
Personally, I don't think we should get too hung up about purely 'non-standard' R/T.
In my view there are three categories of R/T exchange:
1. Standard
2. Non-standard but
not ambiguous, confusing or verbous
3. Non-standard
and ambiguous and/or confusing and/or verbous.
It's only # 3 that we need to address and eradicate - on both sides, ATC and the flight deck/cockpit.