You could have asked this same question in the basic scuba section, FD.
Limited vis in the Public Safety setting is more akin to 0 ft to 3 ft vis. And that is a really big difference.
Utilizing an FFM with voice features is how you communicate with your team then, since you cannot possibly see them. Relying on your instruments when you can see and read them is basic. The problem is that often you cannot read them at all. At times like that a human voice is very reassuring. The harness is a security feature as well, when it is being used. I doubt you are ever going to use either of these items, however.
As long as I can see my instruments, even in 1 ft vis, I am fine with low vis. However it is when vis goes to -0- and I cannot even see my instruments that I always start to feel a little unhappy about it. That is the answer to your question, I believe.
Nobody expects you to push yourself beyond your own limits. You decide for yourself. That is always true in any kind of scuba and at any level. You should always keep that in mind in your open water training as well. If you feel uncomfortable, then you need to train more. Take another class. Dive with a reliable mentor and stay close.
Be really careful about the macho-image man-thing which you mentioned in your post. That could get you into trouble if you push yourself too fast. Everything you do should be comfortable to you, if not a little unusual at first. The first time you do anything you should be with a competent instructor. The next time, then, with a buddy or divemaster. You should learn these skills that you need slowly but progressively. And it should be comfortable for you.
Start out by finding great instructors, and pay attention to what they tell you. Make sure you have quality gear, and keep it serviced regularly, and streamline it. Learn and know how to use your gear and your instruments. Plan your dive, and dive your plan. Finally, listen to the voice inside of you that tells you if something seems right or not.
I would consider 10 to 15 ft vis to be a spendid vista, great even for scootering, although probably at a much lower speed than usual !