Is it permissible to watch educational videos (non-atheistic) by a content creator who presents ideas close to atheism, and is this considered assisting him, especially given that these views do not generate him financial profit?

It is permissible to watch useful materials that are free from Sharia prohibitions. However, one must be wary of those who mix poison with honey and subtly pave the way for destructive ideas. Therefore, those who lack the ability to discern falsehood and distinguish right from wrong should avoid watching such individuals, especially if beneficial content is available from others who have not been contaminated by atheism or deviance.