Safetypee: I agree with your statements and I do not see where I stated anything in contradiction.
I you land on a 3000 m runway with a 737 using rev only you take no risk at all. At 120 kts you need 1600 m and at 140 kts about 2000 m to get the speed down to 80 Kts. Nice to know that you have some brakes on top of that if they perform as predicted. Crosswind and directional control are crucial as you may have to stow the rev but all that is part of your assessment.
JAR OPS as opposed to FAR did go one step further by requesting data for slippery rwy with a 15% factor. The problem is the reliability of the friction measurement. See briefing from Boeing on that subject.
I made myself a table based on the AFM with landing data for various overweight conditions including Vmbe limitations. If you look at them on a regular basis you develop a good feeling what is possible.
Groundspeed is a key factor as I had stated before. If rwy is slippery, slope becomes significant.
When driving a car you know how to decelerate as stop before a traffic light. With an aeroplane it just takes a while to get the same feeling but it takes some effort. You need to take some time after each landing to reflect a bit on what happened. After a while it becomes second nature.
A useful exercise on a very long runway is also: Idle rev and no braking and see how she decelerates by herself, you will be surprised.