I really don't know much about this Priest. I know he is controversial. I am reminded of this passage of scripture:
“Teacher,” said John, “we saw someone driving out demons in your name and we told him to stop, because he was not one of us.”
“Do not stop him,” Jesus said. “For no one who does a miracle in my name can in the next moment say anything bad about me, for whoever is not against us is for us. Truly I tell you, anyone who gives you a cup of water in my name because you belong to the Messiah will certainly not lose their reward." [St. Mark 9:38-41]
Also, we must remember that "Faith healing" - if properly understood - is indeed an Orthodox concept. We believe that there is healing in and through the sacramental graces. Of course, the difference between Orthodox "faith healing" and the charismatic perversion is that we don't teach that people will be healed if they simply have enough faith. Instead, Orthodoxy teaches that God can heal any illness, affliction, or disease, and that He often does so in and through the sacramental graces of the Church. But God may choose not to heal a person in order to allow their suffering to be their cross that will enable them to draw closer to the kingdom. Whereas charismatics believe that it is always God's will for people to be healed, we Orthodox recognize that God often allows us to suffer so that we can learn and grow from our struggles.
This Priest may in fact be doing God's work. But like I said, I don't know enough bout him to state an opinion one way or another. If he is teaching error or heresy, then that would definitely reveal him to be a fraud. But I haven't heard any teaching of his that is outside of the doctrines of the Faith. I just don't know enough about him.
In the end, a tree is known by its fruit. If his work is a divine work, then it will bear good fruit. If it is not of God, then it will wither in time.