Male/female shaking hands, friendshiips, etc.

[Hrvatski Noahid]

The precautions advised do not suggest that friendships need to be avoided. Rather, it applies to actions that could arouse a mental and/or physical attraction between men (primarily) and women in the above listed categories, such as giving polite or affectionate hugs or kisses, or being secluded together (see "The Divine Code", Part VI, ch. 6-7). And likewise a man should not gaze at the body and clothes of women in the above listed categories, so as not to arouse any erotic thoughts about them.

On the other hand, Rabbi Weiner writes (Part VI, topic 6:5): A man should not intently gaze at the form of a woman in a lustful way, even if she is single..."

Friends go out and spend hours together, and I know no man who can gaze at the form of a woman so long without having lustful thoughts.
How can male/female friendships be allowed in the Torah?

Moreover, does the aforesaid prohibition of gazing at the form of a woman in a lustful way not forbid all movies and pictures with women? How can a man gaze for hours at a non-pornographic movie with female actresses and not have lustful thoughts?