Still reeling over/digesting the ending, and thinking back to all the little details throughout the game - for example the fact that Songbird couldn't withstand high pressure was written on the blackboard in Fink factory.
Things are starting to make more sense now after reading more about it, although of course so much is open to interpretation.
The only thing I still do not properly understand is the "ghost" Lady Comstock in Emporia, and that we don't see her again after she breaks down the door to Comstock house; the body in the coffin vanishes, and Elizabeth says the "ghost" is part a projection of her anger towards her "mother" (not real mother of course). But I still don't understand what it is, or where it was brought in from. From what I understand, early on in the game Elizabeth mistakenly assumes she can create realities based on what is in her mind, when the rest of the game suggests that things have to have existed in another permutation in the multiverse in order for them to be accessed through tears. So how on Earth is the deceased Lady Comstock a ghostly image with the ability to make tears to "raise the dead"?