Not sure what era you are referring to Beags, but as the subject is Ascot Ops I assume it to be mine. As a Hastings/Hercules Captain 1966/73 I had little problem with them. My experience seemed to be much like yours and like you as captain I'd make the required dispositions but then send them an "unless" signal, ie "Unless instructed to the contrary intend to depart XXXX at ZZZZhrs for YYYY with Tech Stop at AAAA". Always worked for me, usually dug them out of a hole and allowed me to exercise my "Command Powers". As to the lying toe-rag of a DAMO the only recourse would be a Voyage Report, though that could be two-edged. One at AKR actively encouraged me to submit one against him following a "Mal-Load", reasoning that it might ensure his section be at last brought up to strength!
As regards Crew Duty Limitations, I assume that they are as clear cut as in my day, and you should stick to them. It is for the AOC to decide when and where his GASO's do not apply and to promulgate that accordingly. Ours did scrap Crew Duty Limits once for a reinforcement exercise backwards and forwards to AKR (again!). The top bunk rapidly became a hot bunk!