The main issue with the Dimonds is not that they disagree with this or that point, but rather how they disagree. Their bad will, their bitter zeal, their uncharitable accusations, their demonstration that they are in no way Good Christian Gentlemen like for e.g. St. Francis de Sales and St. Thomas More, but rather radical monks like Luther and others condemned by the Church. Not even the Pope demands as absolute a submission as the Dimonds demand from their disciples, and one can see the sad effects of this cognitive dissonance on those who look up to the Dimonds. The Dimonds basically set themselves up as a Pope or an Anti-Pope and demand submission to each of their opinions.
Personally, I think some magic is just human tricks, while others are indeed diabolical. I consider Exorcisms a better proof of the preternatural and supernatural, and also of the True Faith, since Priests demonstrate authority over demons. I also think NDEs - and the Dimonds did another video on that recently - are a decent proof of the afterlife.