>>212473347Nta, but my understanding of how it works is, if you're doing anything other than sticking to the proven facts of the real story, such as suggesting Dylan and Eric were gay, you should get life rights to avoid getting sued for defamation or libel or whatever else. You never know, the families of the shooters could try suing over "my son wasn't a fag", or whatever legal term might apply to that.
No, life rights are not strictly necessary to make the movie, but you're potentially opening yourself up to getting sued if you're putting any kind of conjecture or interpretation between the known facts. Your other option is to just change the names of everything so you have deniability that "well of course this wasn't a columbine movie, we never used that name for the school or any real life names, any similarities are purely coincidental"