By the time ep164 becomes free (and therefore I can post about it), these theories will probably be either confirmed or debunked in fast pass, but I gotta get them out of my head anyway, so thank god for the schedule post function.
Lenore is almost certainly going to have to beat Annabel at chess now. Ira would absolutely have let them get away with just getting engaged without needing to uphold the chess deal, but our newly-arrived Mr. Entitled (whose name I do not care to remember, much less use, and whom I think we're all on the same page about re. him being their killer) does not seem the type to let that slide. They could just run off together, but I don't think that's likely, because why would they bother with a formal engagement, much less the actual wedding, in that case?
So Lenore will have to play. And if Moustache The Murderer is around to watch, Annabel likely won't be able to throw the match, because if he's played her so many times he'd probably notice if she lost on purpose. So Lenore will have to win fairly. I do think she has a shot. Not because I think she's a chess genius, but because I think her knowledge of Annabel, and her ability to do things that Annabel can't predict, will give her the edge.
Now, it's possible that Annabel does throw the game, and Pompous McBitchface does get suspicious, so he goes poking into things he shouldn't. But I think he's going to do that anyway, and from a story perspective it's more satisfying if Lenore wins fair and square. It also makes Annabel's later faith in Lenore's strategic abilities, from the moment she gets any memories back at Nevermore, make even more sense.
And yeah, I'd bet money that That Fucker is going to go sniffing around where he's not welcome one way or another, whether out of suspicion or anger or jealousy, and he'll discover "Leo's" secret. Annabel will find out he knows, whether because he confronts her or because she figures it out, and she'll make a deal to marry him instead as long as they don't harm Lenore. Thus, the betrayal on the wedding day.
Now, this is of course all just theorising. But if that is indeed what happens, it's so perfectly tragic and it kills me. To quote (or, more likely, paraphrase) another tumblr post, there are two kinds of tragedy: "this is tragic because it was always going to end this way" and "this is tragic because it didn't have to end this way". This would be a perfect example of the latter. It didn't have to end this way, but it did because the characters are who they are.
If only Annabel hadn't kept things to herself (like she always does), if only she hadn't assumed her plan was the best plan available (like she always does). If she'd opened up to Lenore and tried to find a different solution together, they might have been able to escape. If only she had been able to abandon the rules, and step outside the lines. But she's never been able to do that.
And if only Lenore hadn't pulled the gun at the wedding, they might have lived to try a different escape another day. We don't know all the details of what led to the actual shooting, but I would bet that Lenore's refusal to back down played a large part in it. Because that would fit the tragedy of it all.
If only they had trusted each other. But they didn't. It didn't have to end this way. But it did. All because the characters, in the most crucial hour, made the choices they always do, and thus sealed their fates.