"Climbing well" , maybe just climbing is, in itself, subjective.
[...] Not thru debates on the Interweb, I am sorry to say.
Knowing our limit is certainly important. One can be a good 5.11 on face climbing and a poor one on slab climbing. As I had carpal tunel, I wasn't abel to climb hard crack because my hand opened. So, I won't say that he wasn't a 5.11 climber, but that one of his weakness was slab climbing. If you remember slab direct, there is a piton under a flake and you can place two or three stopper higher and you have a run out of 40 to 60 feet to the next protection. the slab/layback move is very stressful and mak the fall dangerous.
Is it safe to know your limit in different kind of rock or controversial? . The 5.11 climber in "diedra" roof, at cathedral, will rate it 5.10 and, as I am/was(sniff) a 5.9 slab climber, I will rate it 5.8+ becasuse I do a friction move in it. if we do a debate, like a brain storming, I think that we can be safer. If you consider me as an enemy that you must fight, it is not the good place.
In the "art of leading", John Long, one large part of his video is to learn climbing technique. Although it is better to climb every day to learn it, some people, far from a cliff, can need a guide to bring them outside there confort zone. Like when I bring a 5.11 climber in a 5.7 slab to see his reaction under stress. He bail and did it in top rope....feel humiliate...and think that I want to laught at him.
In master of stone, we saw a lot of the technique use by John Long, but done in one movement in marginal hold. I am not sure that master of stone is for begineer?