If changing missions there are a lot that need reworked.
Plus your Cardiac Arrest suggestion is only part of what it would need. These are now typically 2 DCAs, or 1 DCA plus 1 RRV and 1 RRV/OTL/GP/DR/HEMS and in places that run CFR they are there too.
An arrest gets a big response typically these days rarely would it be left to a DCA and 1 extra.
Reason for this you would have 1 person on breathing, 2 or 3 rotating for compressions until autoPulse or a LUCAS is set up, 1 person on IV access and managing drug and fluid input and the the most senior on scene monitoring patient, responsible for AED and managing their care typically this would be an Advanced Paramedic or Dr. That's 5 or 6 minimum crew. Any more and they will rotate on compressions team until either they get autoPulse going or the arrest is called life extinct.
Very rarely these days you are likely to see a DCA work an arrest on their own yes possibly until more resources turn up but to transport the patient with 2 crew would rarely happen. As that would leave 1 person managing the patient on their own for a while and often would not be a positive outcome.
A friend of mine suffered major heart attack 2 years ago and was classed pre arrest by responding crew, before he was taken to hospital 5 mins away they had another DCA and a RRV with paramedic and doctor on board. Just incase he arrested. During transport he had the doctor and 2 paramedics in back of ambulance. So not even an arrest at time but he had a full arrest response. He didn't arrest then but decided to keep that for when we visited him but that was his style. Now though he is returned to normal after quadruple bypass.
As to calls that need reworked all the medical ones need revised but again that needs more use of gp and Hospital transfer system added
Other calls are basic naming changes these are insignificant really, Road Accident I'd say is acceptable general descriptor for any on road incident really. Yes accident has been dropped due to there being no such thing as we are in a blame society now.