Is there a way to mark favorite podcast episodes?

I don't believe there is a "favorites" menu, but as an alternative, you could go to the episode menu and choose "Save Episode". Then a "Saved" tab will appear in the Show screen (go to "My Podcasts" then click on a show that you're subscribed to, to show the list of episodes). The "Saved" tab appears to the right of "Unplayed" and "Feed", and these episodes will remain there even after you've listened to the episode, which makes it easy to go back to them later. It's not a "Favorites" across all shows, but it's sort of a "Favorite Episodes" list within each show.

There isn't as far as I've seen. what I've done in terms of this is saved the episodes that were my "favorite" or ones that I "loved"