I was wondering if they'd address Carol Ann Susi's passing on the show. I think they handled it well. I hadn't heard anything in advance, show wise, so it was a bit of a shock. The Nathan Fillion cameo, however... It seemed a little flat compared to what they've done with others.
I don't think so, I watch Castle regularly and that's pretty much what he looks like. He's definitely aged a bit and put on a decent amount of weight since he was on Firefly, sadly he ain't Mal Reynolds no more.