First of all the contestants knew what they were getting in to when they signed up.
Regarding critiquing: The Chofetz Chaim does address it in his sefer, but he does so regarding a speech and how you may change someone’s mind that the speech wasnt actually good rather delivered poorly. I guess you can apply this here, but I dont think its the same thing. I would say (for what my opinions worth) that if you want to watch the movies, watch them without reading the comments from the peanut gallery.
About Chukas Hagoyim: Last time I checked a message board wasnt the idea of a Jew….. Just sayin