It's also possible, I think, that we already have enough information to solve the problem highly satisfactorily, but that it's difficult of access owing to the need to multi-disciplinarise one's self as a scientist, when we're all trained to be so specialised.Yep. And we don't have near enough information to list even the major possibilities - let alone try them out in a lab.
Of course. It happened somewhere on the planet earth, sometime in a span of several hundred million years, so long ago even the rocks have largely vanished. It may have happened only once.
The surprise is not that we don't know what happened, but that we have made any progress at all in investigating the matter. That's an amazing accomplishment, in such a short time and with so little hard research (compared with the need) devoted to the matter.
That we don't have enough information yet, would be lesson one. That there are a lot of possibilities we haven't even thought of yet, would be another likely implication. That a lot of solid and exhaustive research remains to be done, is pretty obvious.
When you're guessing you're guessing. No reason to be coy about it.
My point is simply that what we do know matches the predictions of some kind of assumed general or abstract Darwinian evolutionary process perfectly, and other theoretical approaches not very well at all.
That Life's so adaptable and robustly survivable (e.g., stunning variety, evolvability, extremophiles) tells us that it's clearly not a fragile 'one-off' kind of a phenomenon, and therefore that there's likely to be nothing hard or extraordinarily rare & difficult about its origin. I suspect that it'll seem all too obvious once a solution's been accomplished.