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As to what would have made the common ancestor of all life alive? Well, that would be a question of definition, since there is no evidence of what it was. Since it was, by definition, the common ancestor of all life that is around today, at a minimum it would have had to have had offspring, more than one, one assumes. It would have had to have had some kind of chemistry and physical change analogous to metabolism in order to sustain itself, unless you are going to posit some primeval inedia, in which case you're going to have a lot of 'splaining to do about what its offspring were made of. Did it use amino acids? I don't know. Maybe it, somehow, did without those and, maybe, its offspring developed a means of using them. But, you forget, I'm not the one claiming to know anything about it that would cut the mustard as science.
I notice you haven't touched the containing membrane question. Hard nut to crack. Hard to imagine how that could have happened through non-biological means, isn't it. Not to mention what it would have been made of without the proteins produced from the molecules produced by DNA and formed through complex cellular actions on those. And, as I pointed out, if those were there, where the world did they come from and assemble by random action? It's hard to imagine how they could interact if they were uncontained. But, then, some of the same questions would be relevant to the known means of reproduction, anyway. It's harder than the chicken and egg question. At least we know there are chickens and there are eggs and that there were eggs before there were chickens.
You see, "abiogenesis" is quite able to generate material for the ID industry, I think far better than it can science of knowable reliability. I'd say junk it, though I'd imagine there are too many people getting paid under that umbrella to go through the motions for that to happen. And the fundamentalist materialists would go into withdrawal without it.