> The "ABC" of airway, breathing, circulation they taught us may not be current advice.

The version taught in Australian first aid classes is DRSABCD: check for (D)anger, check for patient (R)esponse, (S)end for help, (A)irway, (B)reathing, (C)irculation.

Part of the reason they teach "ABC" is it is simple and easy to remember, especially in an emergency. I've reread DRSABCD a dozen times now and I guarantee I will have forgotten it in a few minutes. Case in point, you missed (D)efibrillation...