Sorry to have been only a silent observer in these discussions up to this point. I have been reading with great interest.
Have you talked at all about sympathetic attraction? It's a big deal for the Elizabethans that people with a similar life experience will be attracted to each other, and there are many examples where Shakespeare shows characters who will ultimately fall in love having similar experiences. Rosalind/Orlando spring to mind. Not only that, it's pretty common and accepted that sympathetic attraction happens immediately, that is people who are meant to be together will immediately fall in love. I think we moderns are skeptical of love at first sight; maybe we put greater emphasis on making decisions intellectually. Elizabethans may have been more inclined to assume love at first sight was a good indication that two people were a good match.
The best example I can think of is the opening of Cymbeline. The first scene is essentially a narration (which is almost unreadable in its density). It lays out the all the ways that the lives of Posthumous and Imogen (or Innogen if you must) are similar. Shakespeare's audience would get from that scene: "Wow, I can hardly wait to see what happens when these two meet." When I directed it, I had Imogen and Posthumous circle each other, slowly spiraling in to an embrace all through the opening narration. We'll save that discussion for when we get to it, but it makes Posthumous' betrayal that much deeper and justifies Imogen's faith in him to the end.
On the other point, I think Lady Montague may have been killed by financial necessity: killing Lady Montague may save an actor if he comes back to double as the Apothecary. I haven't done the math on this one yet, and I'm sure there are other possible doubles, but I have been in one and seen one production that used Lady Montague as the Apothecary. He, Friar John and maybe Mercutio then have to return as the Watch in the last scene.