Figaro is so great! It is the first opera I ever fell in love with. (And it was the opera my voice teacher made me learn some (Susanna) arias from, back during my abortive efforts at voice lessons, so I know all the words from, say, "Deh vieni non tardar" even though I realized while watching that there are big gaps in my knowledge of how it's translated.)

So -- now you've made me think about what the music is saying -- the Count's "Perdono" is moving, but it's the Countess's "Più docile sono" that really breaks my heart (and also the "Tutto contenti" afterwards, although like I said in this particular production the "Corriam tutti" got me hard) -- so I think maybe the music is saying that the Count may or may not reform (and his behavior certainly doesn't point that way, as you say), but the Countess will, in the end, be all right; she'll find her way. I have to believe that, after listening to her sing that.

"Tamino mein/Pamina mein, O welch ein Glück!" is, I think, my favorite line/exchange in any opera, ever. It's the kind of thing where I almost have trouble talking about it, I feel so strongly about it.

I really like your take on "Deh vieni non tardar" -- that makes a lot of sense, that it means something real, just not what Figaro thinks it means :)