Please forgive my poor formatting, I am typing from my phone.

To the first part, my argument is not that these are states of self at all. It is my view at this time that the idea of rebirth is a natural and necessary outcome of a view of the universe where matter and energy are conserved, not destroyed. If there is no soul, no ethereal presence, no "I" in consciousness and the like, then all of these do exist and will continue to exist. Just as the matter and energy which comprised me may change and break apart, it will also recombine and form the building blocks of new people and new life. For death to be an end, for it to be annihilation, there would have to be a self, a soul that is eliminated or removed at death. As I do not see one, it does not logically follow that death is an end, just another complex rearranging of the matter and energy which comprises the universe.

To the second, I disagree with your assessment. It is nibbana which is ultimate truth, the realization of things as they are. The dharma is the teaching, the path that guides us into crossing over into the realization of nibbana. I believe it is in the middle length discourses where he states that the dharma is a raft for crossing over and not for clinging to. Like a raft, one uses it to cross over, not to carry on their back. This does not mean we should not use it, just that we must be willing to put it down when we have crossed.

To the next, it is always possible I am misunderstanding people here! We're talking through text and that is a really bad way to communicate in a deep and compassionate way. Sadly what I see here is any disbelief in the idea of supernatural stuff be responded to with negative vitriol. It was enough that some time back, I had a very negative view of Buddhism after visiting this place. It was only by a strong personal attachment I feel to the teaching that got me to keep reading Walpola, Thich Nhat Hanh, and Bhikkhu Bodhi, and got to me realize that I should keep on this path regardless of what I see here. After all, I saw much on Buddhist thought that fit with what I saw in the world, and Buddhist thought then helped me to see things I had missed. I would be a fool to turn away from that just because of the hostile responses I see here.

I'll also note that I don't describe myself as a Buddhist as I know that term comes with much cultural baggage. I am not a Buddhist. I have a daily mediation practice (up to 30 minutes, woo), I just got my copy of the Majjhima Nikaya yesterday, and I practice being a good, compassionate person to the best of my ability. I've even cut down on how much meat I eat considerably, something I never thought I'd do, but I did it because the argument against it was sound. All that said, even still I don't claim to be a Buddhist. Not above and not in my infrequent posts here. The title isn't important and I wouldn't want to be bogged down trying to defend myself using it. I'd rather focus my efforts on other efforts.

My point in posting above is to say that there are many who are interested, but they need a teacher, someone who can help them to understand. Just telling people who are refugees from Western religion about hell realms, rebirth, and karma as supernatural forces requires either they simply believe or people who can teach it in a better way. Most secular Buddhists I have met do not disregard these things, they usually just need to understand them differently to see them in the world. They are drawn to Buddhism due to its dislike of belief, but then feel like they have to believe. This is a different audience, and it is one that needs a really good teacher to convey things in a way that can be grasped.

In regards to your view on science and Buddhism, I am in total agreement! What I find beautiful about Buddhism is that it argues about what can be discovered by looking inward. It identifies patterns that are generally applicable and as time goes on, I see science increasingly confirming more of it.

I'll also add that there is also very likely the colonialism stuff you've talked about. That's one of the reasons I don't call myself a Buddhist. But of the secular Buddhists I've spoken to, they don't seem to be saying that Buddhists missed something and they can add to it, any more then the different groups are saying the others are totally wrong and need fixing. By and large it is a disagreement over particulars, in interpretation. Yes, if someone out of hand says rebirth doesn't happen at all, that's equivalent to a someone claiming to be Christian but doesn't believe in the resurrection. There's definitional problems there and that isn't gatekeeping. But to interpret what that means is a different thing. You've already read how I interpret rebirth, there are some who have a view that rebirth is equivalent to a soul, and others with more complex views. But at the heart of it is the understanding that there is creation, destruction, and recreation, in a constant cycle of arising and collapsing and rearising.

I totally agree that people shouldn't try to take rebirth and karma out of Buddhism, that's like taking Jesus out of Christianity. The point I am trying to convey is that there are many who want the dharma, who want to see the path, who crave the end of craving, but they need a teacher who can frame this stuff in a way they see. We are in the 21st century and many, if not most or all, are in the West. The idea of rebirth is foreign and going from Christianity's soul to hearing about rebirth leads up wrong views, but we need to be mindful, as us condemning wrong views in an unskillful way may snuff the potential awakening of another. That, I hope we all agree, is not a good thing.