As much as I dislike anti-gay, racism, etc, I have to say everyone has a right to their own opinion and I would fight for their right to speak freely, even if I disagree, as I expect the same right. That being said, this forum is not a "public" forum as it is commercially operated and privately owned and therefore has the right to place rules to reduce hostility and unnecessary attacks to help the forum maintain stability. When it comes to whether or not someone should be allowed to post "homophobic" (I quote as what may or may not be considered homophobic can be a gray area) remarks I say err on the side of caution. If you truly wish to convey your belief, you will acknowledged the large gay community on this forum and use tact to provide your feelings in a manner in which this community can acknowledge and potentially respect (regardless of agreement). To do otherwise would show lack of interest in discussion, merely the need to flaunt your opinion to instigate others. Mods will always side with homosexuals in an instance of potentially "hostile" posts in regards to homosexuality as the defense of ones' being is more valuable than of ones' opinion.
In response to op, it is important when creating law to be extremely clear in definition. While absolution is near impossible, this one is far to vague. If you wish to prevent children from being exposed to homosexuality in school, then it should specify. Propaganda can range from gay pride rallies to two men holding hands at a public park. How does this apply to content that is intended for adults, but could be accessed by children? Keeping true to the site, I'll use an example in video games. Should a game like Mass Effect be banned because it can potentially have homosexual relationships even though it is intended for a mature audience? How about flamboyant non-sexual gaming characters like Tingle? Its simply absurd. This bill potentially sets up a form of segregation and is easily a stepping stone for more serious restrictions.