Not bad at all, and I love the theme!
Initially wanted "nose" for 1D: What dogs "shake hands" with, but Frannie thought I was probably reading a little too much into a human handshake, to think that it could involve as much information as whatever info a dog gets with a sniff, and she immediately corrected it to PAWS. And I guess 5D: Phonograph needle (STYLUS) might seem a little outdated to some, but it comforts me. And besides, you've got REN (7D: Stimpy's TV pal) right next to it, so that makes up for it, right? Or is that, too, already outdated? ... god I'm old... but hey! I'm not old enough to actually have listened to AMOS (9D: Half of an old radio comedy duo), so that's something, right?
I like the vertical tens, PEJORATIVE (11D: Disparaging) and NATUREWALK (28D: Activity led by a park ranger, perhaps). Also liked the clue/answer 53D: "Hot" lover (FLAME).
Not a ton of good stuff to call out, but very little bad to say either, and sometimes that's a very good thing.
Also, does this puzzle count for getting us one degree closer to KEVIN 45A: Bacon of "Mystic River"?