yankel, a fair question on who is a talmid chochom. Your definition are the right ones. There are mentions of T’Ch that describe his behaviors, which can be considered definitions. For example, if you see a T’Ch going somewhere inappropriate at night, you don’t have to tell him in the morning because he surely did teshuva. So, this means, T’Ch may do an aveirah, but he reviews his actions daily.
The problem with these definitions is that they require close observation and our own judgment. Sometimes, you can make the judgment from the stories. for example, about spare time and priorities, there is a story about R Soloveitchik getting into analysis of a Rambam during a Thursday afternoon class when he was usually flying from YU home to Boston. When someone reminded him that it is time for him to fly home, he said – nobody is leaving this room until we understand this Rambam …
So, correlation between different chachomim seems like a reasonable method to me. There is nothing new here. This is how haskamos work!
This method relies on halochos – how one T’Ch should relate to another. And it is observable – there are witnesses that saw meetings and talks, and books where Rabbis mention or give haskama.