Conspiracy theories appeal to people because the complexity of the world and lack of coherent narrative to it make them react with fear and anger. There are totally conspiracies that exist and we should be fearful and angry about them, but for some people that becomes their dominant modality. Illnesses like paranoid schizophrenia are completely unchecked versions of it which is why they're so prevalent in gangstalking.

There isn't really crossover in content apart from the generic conspiracies that explain who is gangstalking you. Gangstalkers might think it's the government or gangs or a cult, Qanon is a more structured understanding of those things. That structure reverts to the same democratic centralism of most conspiracy theories. Gangstalkers fold in and it's a buffet of content that rewards original research into its canon, but a lot of their gangstalking stories are like "I saw a red car three times in one hour" or thinking the bus drivers have it out for them. It doesn't have the same legitimacy as the other conspiracy theories which make up Q.