Honestly I like the European system better, where all diving is treated as deco diving. "Optional" safety stops are silly, if you can't do the time, you shouldn't do the crime. If agencies "enforced" a mandatory stop, buoyancy control would necessarily improve and exceeding one's NDLs wouldn't sound so scary.
Except for one small detail, the entire concept of recreational diving is based on the assumption that if a problem develops you have immediate access to the surface. Having 'mandatory' stops negates that assumption.
There is a practical qualitative difference between diving in situations in which you can safely ascend immediately to the surface and situations where you cannot. So, IMO, diving in such a way that there are mandatory stops is not practical recreational diving.
Regarding the 'additional safety' of nitrox, the two sides of the coin-both correct- are that A) all other things equal, less N2 loading 'should' result in less risk of DCS. That's an assumption, but based on widely accepted ideas about DCS. B) In order to absolutely state that a given practice presents less risk than another, statistical evidence is a necessity, and to date there are no statistics supporting it.
I suspect some dive physicians recommend divers who have demonstrated risk for DCS (like by getting it!) to use nitrox on air tables because they believe that it's at least theoretically beneficial. I personally would not use an air computer with nitrox, particularly with lots of repetitive dives. I want to track O2 exposure as well.
If I were in the OP's situation, I would study the basics of decompression theory and learn as much as is practical about DCS and dive behavior that appears to be associated with it. I would do very long safety stops, and I would conduct dive profiles in such a way as to minimize N2 exposure. I really believe that knowledge is important in this case, and that good understanding of the basic models can result in more intelligent dive behavior, which in turn is likely to be the best safety practice.