Missing from your draft table of contents (but maybe covered in 10, 11, 13,14  and definitely 8 with lawyers)
should be how to do deal with raging narcissistic behavior that will come your way when the gay spouse
decides you're worthless and they want out of the marriage.   
That is; once I got my head around the lies, cheating, gayness, and even divorce  I was unprepared for the abusive narcissistic rage ..the pure evil..   A gay narcissist not getting what the want is a very dangerous person.  

Otherwise looks good.

Excellent list of topics.  It is probably included under "Who to Tell" but just wanted to emphasize that a discussion about whether it is okay for you to "out" someone or not and under what circumstances would be useful.  The importance of controlling the narrative of your divorce and the years you spent with this person.  Protecting their privacy means keeping your own truth locked in their closet ... something I am very much against.  I fully support LGBTs right to choose when or if to come out, but once someone has crossed over to deceiving a straight spouse/partner, I believe they lose that right to our consideration. 

I second Rob's gay narcissist suggestion.  So many of us here are really dealing with being married to narcissists who happened to be gay or something or N's with no boundaries. 

We often talk about amassing documents for the Divorce Attorney.  A checklist of documents commonly needed for a divorce would be great.

I think for me , when I first found gay porn over 20 years ago now, the first word I think of is shame, horrible shame. So because of that, I told no one, not a soul, and I let him convince me it was nothing, blah, blah. And because he was seemingly a good father and husband, I believed him. My hope is that no man or woman ever needs to feel shame again when they find themselves in this situation, they can talk about it and get themselves out of it. No more shame.

What is so difficult about being married to a closeted spouse is being in the church environment. It's common to act like homosexuality or being gay is something "out there" beyond the congregation. It's never acknowledged that single or married people (people married to the opposite sex) in the congregation could experience homosexual feelings let alone act on them. Being involved in gay porn is acting on those feelings and goes beyond the sanitized term of "same sex attraction" that very traditional churches are starting to embrace and acknowledge within a congregation. If the person acts on their same sex feelings it still is not termed gay behavior. The deceit that often goes hand in hand, especially with married spouses, who have "same sex attraction" or gay feelings is never mentioned. When someone talks about his/her "same sex attraction", usually after being caught, they are also deemed honest and given the benefit of the doubt even if they've been deceptive for years. Yes, we should love and accept people, but people should be honest and not deceive their spouses and families or act as if they'd never act on those feelings when that's exactly what they do. Many religious people hide behind a spouse to look straight. Many religious people immerse themselves in gay culture and then demand forgiveness from the spouse who they intentionally duped. Sadly, male religious leaders in particular support this forgiveness idea when the spouse knows there still is great emotional danger in trusting a deceptive spouse. The straight spouse (often a woman) is labeled unforgiving and even shunned by a congregation for standing up to an unfaithful spouse or for "gossiping" as to why her marriage fell apart. The straight spouse becomes twice victimized, by the spouse and by the church for not just overlooking the deep pain and broken trust that is experienced. The popular church motto is to reach out with love toward the person with "same sex attraction" who married an innocent person, a person who thought he/she was entering a heterosexual marriage. Instead the straight spouse was pulled into a mixed-orientation marriage unawares. Surprise! Then the "forgive and forget" advice is administered on the straight spouse and, of course, the expectation to silence the devastating experience and to only say positive things about how the church leaders handled the matter. Ouch! Many church leaders don't want this talked about beyond their method of handling the situation. It is a complex situation, but it would be great to reach out in love to the straight spouse too and not just lovingly embrace the person with same sex attraction. Again, it would be wise for all counselors to grasp the fact that deceit often continues and doesn't just go away in these marital situations. I guess church leaders can be indirectly or even directly part of the gaslighting process too.