Wow - a lot of fences being built here.
I will dive with anyone once - if I think at the end of the dive that you are a risk to my safety we won't be diving again. Really doesn't happen much - I am pretty much responsible for myself in the water, from a safety point of view buddy is just a potential supply of air and one I prefer not to rely on. If the dive is one where my safety requires that supply of air to be nearby and available I probably won't be doing the dive - it violates my solo dive in your head rule.
Frankly I dive solo in my head, but try to work with whatever system my buddy wants to implement to ensure that they are comfortable diving with me. My dive rules in no particular order:
1 If you are diving with me YOU are responsible for your own safety.
2 I will help to the best of my ability, but my safety comes first.
3 I will share my air, unless I need it to get back to the surface.
4 I will tow you to shore and call the ambulance - unless you are too big and heavy to do that safely.
5 Have a heart attack whatever, will bring the body to the surface - if I can.
6 If you are new or lack confidence we will do as many easy dives as it takes, I can always do another dive tomorrow with someone else.
7 Do something really really stupid I will stand back and watch, if rescuing you will get me killed.
8 Slowest diver wins - want to race all over the reef - feel free, I just won't be too close behind you, probably back where you started - taking a picture of that cool critter you didn't even notice.
8 I will keep track of your air - I might need it

- but my air supply is the one I am tracking if I get low I am going up - you are welcome to join me(and I will let you know). If you don't I am going up anyway. If you are low I am going up, again you are welcome to join me.
9 Want to do a buddy check - great otherwise I will be looking at you and checking anyway. I always check my air just before getting near the water - every time - three breaths - watch the SPG - fill the BC - fill the drysuit. Learned the hard way

I am likely to forget other things so feel free to ask if I really meant to try to dive with no weight in a dry suit??? Yes it has happened. Doh
Too much plan the dive dive the plan - what happened to lets go see what we can find - here are the limits we operate under - no deeper than X start back at Y, here are the issues to remember about this site.
I am down there to look around and see interesting stuff - if the interesting stuff is outside the plan then evaluate the change and if safe go look. Nothing I have yet to see under the water is worth dying for however - come back and look another day with the right gear.
Just my rules - everyone has theirs - if they conflict - we won't do more than a single dive, but it is probably you not wanting to dive with me cause I won't follow the "rules".