I doubt it that the Wikipedia introductory sentence warning about damaging a living person refers solely to:
go ahead, say what you want as long as you cannot be caught from the legal view point you can write everything you wish. 

I think Wikipedia refers to some honor and honesty in talking about a living person who can be damaged in his/her reputation and can suffer financial damage as well in his business .
So, it is a question of honor and good editorial behavior in keeping with the truth.

You are pointing out the fact that the Wikipedia article on Ruggero Santilli talks about fringe. The difference between  what that article says and what the Oxyhydrogen  article says is the difference between being fair and being recklessly mean and damaging.
This is my example:

Steve is a photographer and some of his work is considered unprofessional , childish and "fringe" 
(physicist Ruggero Santilli  who is proponent of ideas some of which have been considered fringe theories) as it is in the article about Ruggero Santilli

Steve is an unprofessional photographer and he is an unprofessional "fringe" photographer
( fringe physicist Ruggero Santilli) as in the Oxyhydrogen article

You are saying that Santilli is clueless about electrolysis and therefore all his work is 'fringe" ......
how about his books in other subjects published by Plenum, Springer Verlag, Nuovo Cimento?Did you read the? 
You say that you want sources, peer -reviewed article and yet you do not like the International Journal of Hydrogen Energy and cite Calo as having negative comments...how about the positive comments on Santilli's work by Cloonan and Trell in the same Journal? They are University professors .... you also do not like their universities? Do they have a poor reputation in your view? How about Santilli's article in the American Institute of Physics ? AIP also has a poor reputation? 

I added  verbatim to the Oxyhydrogen article only what Wikipedia has in the other article about Santilli. You are confusing people who sell stuff on TV and defraud customers, from the work of reputable scientist who publish and work and are seeking the truth as much as you do and because of this you call  "fraud, bogus, fringe, nut job. Bunching these two categories (the TV fraud and the researchers)  together is not "seeking the truth" but being reckless and damaging, especially when it was pointed out to you without calling you bogus, nut, fringe ( which could  be justified by par condicio) but I am not doing it for respect toward the readers and especially myself.
Please do not go back to ethics.
Scuranova