I actually read the whole thing. I deserve combat pay. It is awfully rambling and repetitive, pulling in a whole bag of somewhat related issues as you tell us about Dissident's subjective experience in dealing with antis over the years. One summary might be, "People who disagree with Dissident are ignorant, stupid, and/or morally suspect."
To get clarity you've got to pick specific issues and isolate them from the surrounding context.
Underlying much of what you say is your vision for the Good Society, achieved by a collection of quite radical readjustments. There are many separate issues that smart people of good will could disagree on in terms of how to transform the world.
One initial reaction: We could do much better completely forgetting anything to do with children's sexuality. It is as you note an emotional issue and you raise so much else that wouldn't have such strong feelings involved. From memory, your other worries for children include:
1. compulsory schooling.
2. driving in private automobiles.
3. oppression within the nuclear family.
4. adults as a class seeking and exercising power over children as a class.
5. suffering in Third World children due to international capitalism.
I could think of some others you left off the list, notably:
6. climate change threatens children's well-being throughout the world.
7. societal support for parents in raising children is very meager in the US (e.g. no subsidized high-quality child care).
8. many children cannot look into the future and see employment that earns a living wage.
9. racism affects the lives of many children of color and it may get worse.
You say all the antis assume the world can't change. Obviously vast numbers of people don't think about society changing a great deal, whatever their beliefs. Why should pro-legalization folks be different? I suppose because it's hard to see a path from where we are by a series of modest changes to a world where adult-child sex is accepted. If what unites people is the holy grail of making it accepted, you have to imagine a world that is quite different. Well, I can imagine a world that is different in dozens of respects that are independent choices. Legalizing adult-child sex is one of the least important I can think of regarding children's welfare.
The complaint you lay on "antis" is assuming the world can't change. I'd frame it differently. What everyone has a much better shot at agreeing about is the way the world actually is right now. I dare say most people are incrementalists, wanting to implement change one step at a time based on where we actually are right now. Proponents of a variety of beliefs could all share this criticism of the incrementalists... those hoping to make the world a Christian state, those bent on space colonization, those who want total disarmament, radical greens who want a drastically reduced carbon imprint, even the voluntary extinction people. Any fierce commitment to a big change from the way our world works is going to give rise to a criticism of incrementalists. Pro-legalization of child-adult sex is just one of a large family.
It's fine to think long-term thoughts, but it's hard to gather many people into a consensus. Each group will argue that it has the correct political line and there's no sign of cohesive radical political parties forming.
Maybe you will get support from the less intellectual GCers with, "Well, I guess Dissy knows the details and I don't, but he's fighting for what I want, so he must be right". But most of what you suggest is hand-waving "come the revolution, all will be well", bypassing all the difficult, thorny questions that will divide people along the way. It's not much different from what lots of Trump voters said, "I don't know the details, but Trump talks like I think, so I'm going to vote for him and he'll work it out".
The narrow-mindedness you ascribe to antis is better thought of as the vast majority of people being incrementalists.
All those other groups I mentioned -- ones wanting the Christina state, space colonization, voluntary extinction, etc. -- will write scathing critiques of you for failing to address the truly important questions -- you're just committed to the status quo, they'll say.
There are of course many more issues to be addressed, but I'll start there.