Just listened to the Odo show this morning. Great stuff! Odo was my favourite character from the start of the show, and while that lessened as the show went on - not because of anything he did wrong but just because other characters became equally awesome - he's still a fascinating character and worthy of even more discussion than you had time for in this show.
You discussed Odo being grumpy and defensive at the start of the show. I think one of the reasons for that is his upbringing - while he was nominally brought up in a melding of Cardassian and Bajoran culture, he was never for a second allowed to forget that he wasn't
one of them. The things he says in "The Forsaken" make me think of an abused child - he was tested, prodded, used as simple entertainment almost like a circus animal, but never respected as an individual. That would lead anybody to distrust and general grumpiness, I think. But as you say, it's the relationships that he slowly allows to develop with the other DS9 main characters - sometimes even against his own intentions - that slowly drag him out of that until he's actually quite warm and comforting by the end.
Two episodes I'm surprised you didn't mention though - maybe you just didn't have time - are "Crossfire" and "Chimera."
The former, even though it's a comparatively small and inconsequential episode, is one of my favourites because it just breaks my heart. I think almost all of us can relate to what Odo goes through in that episode - the unrequited love, unable to bring yourself to declare you love a person in case you're rejected and lose everything, and in the meantime tortured by watching that person have relationships with others. I think that might be the most broken up emotionally we ever see Odo.
And "Chimera" is an amazing episode that manages to combine the deepest exploration yet of Odo's nature as a changeling with a love story that is so much more powerful than almost any other in Star Trek
. There's some great discussion of the episode in TheGodBen
's review thread, starting on this page
Keep up the good work!