Those are functions of Plex, if both questions are about Plex. As far as the 24p, go into Plex preferences, Videos>Player, and turn on "Adjust display refresh rate to match video".
If you pull up the TV info bar where it says 60hz normally, find a video that Plex says is 24p and play it, then pull up the TV info bar and it should say 24hz. Works for me anyway.
Sorry, I should specify that's me watching the video through Plex on my Mac Mini, not via the TV player. I've never tried that, my backup player is my LG HTIB which does a pretty decent job of playing videos too.