It is NOT the job of the dive guide/ divemaster to keep you out of trouble. It is YOUR responsibility as a certified diver, to dive within your limits to minimise the risks associated with diving (ie, watch your air, control your buoyancy, call the dive if you or your buddy just isn't feeling it for any reason).
I agree with you in theory, but the way diving shops is run in sharm you WILL have atleast one guide with you on the dive and that guide is generally an instructor or being trained to become an instructor. Many of the shops dont hire any diving staff thats not certified as instructors due to the fact that for every foreign staff they have, they need to employ a certain number of locals. IIRC 7 locals to 1 foreigner.
A divemaster can only guide, while an instructor can both guide and train divers so you rather hire one person that can do two jobs than two persons who can only do one job.
Now all this rambling adds up to the fact that you WILL be in the water with a guide that is considered a pro, with the liabilities, insurances and responsibilities this entails and they WILL do their utmost to keep your ass safe and for all the "serious" dive ops down there that begins in the bus on the way to the jetty (or marina) where youll be given practical instructions with regards to the jetty, the boat and the departure procedures (which btw depend a lot on the mood of they for the police there).
It continues on the boat with nitrox analysing and logging and other safety-essential procedures and most importantly a thorough dive brief.
If you use your ears and follow the guides instructions all this IS designed keep you out of trouble and if you choose to ignore it, they will try to stop you and they WILL stop any divers they deem to be endangering themselves and/or fellow divers from diving with them!
Now of course, theres always some dive ops around that dont give a damn, but it shouldnt take long to figure out if youve ended up with one.