You know, personally, I don't think the rumours of Trump being an active foreign agent instead of "just" a narcissist grifter are useful, because they can be used to argue that things weren't already pretty borked before in the status quo.... (and I think they are wrong, personally)
But I do have to admit - if I was a foreign agent wanting to destroy the US and its influence in the world, I would basically do exactly what he is doing.