I think this leads us back to the "Featured Article" standard for measuring our best editors. A featured article will be:
well-researched: it is a thorough and representative survey of the relevant literature on the topic. Claims are verifiable against high-quality reliable sources and are supported with citations; this requires a "References" section that lists these sources, complemented by inline citations where appropriate;
"Must visit a library" is practically built into the requirement, if not the best possible web search.
It also helps that the featured article status is discussed by multiple Wikipedians. That means it really represents, by consensus, the best that Wikipedia has to offer. We might disagree about whether it's more valuable to clean up an article, create a new stub, or merge together a bunch of smaller articles. But a featured article is the closest thing we have to "objective" quality.
A trusted editor would start with at least 2 or 3 FAs... and maybe throw in some other requirements like "never been blocked", just so we can exclude jerks.
The idea behind a trusted editor is not to create some kind of untouchable class... it's to know that certain people "get" Wikipedia *and* have valuable expertise. It means that we can actually entrust more editors with tool that we'd only given to admins until now. And it makes it easier to spot someone who, by the widest community standards, has offered huge benefits to the project. Marking their status would be to the benefit of newbies AND veterans who are passing by a stranger.
That's okay, Philippe, you'd still make a great admin ;) Some people are given the tools because the community has entrusted them. Other people should be given some of those tools if they've proven that they understand the hard work that goes into our highest quality of content.
I couldn't meet that standard either. Maybe that is one reason why I prefe as a standard for our editors, not that one has acheived a certain level of quality, but that one understands and appreciate a level of quality. Thi is the rationale for my proposal for a tutorial for anyone wishing to register, above. If all registered users went through thaqt workshop, it would make it all the more likely that they could recognize editors who are exceptionally skilled at recearch and attuned to our policies.
Let's create better members of the community. then they will naturally promote and respond to better leadership.