So, Season 3 is probably my best season (I know that's the complete opposite to a lot of people

It's the first season I watched when I was a young kid, and I think my first introduction to Batman as a character, so naturally I have more of a soft spot for these episodes.
Few things about the third season I wanna discuss with you guys.
Firstly, does anyone know why Frank Gorshin only made 1 appearance as the Riddler during this final season (not counting the character's appearance in the penultimate episode). Is it known whether Dozier & co tried to get him back for more episodes during the season but he was too busy? Or had he decided to leave the show altogether and so it would have been known at the time amongst the cast and crew that 'Ring Around the Riddler' was to be his final episode?
Next, how different would season 3 have been with the presence of Julie Newmar? I like Eartha Kitt in the Catwoman role, but I can't even envisage Julie in a season 3 episode for some reason. Maybe it's the singular episode format, the more simple storytelling. I don't know. I can't even imagine her with the minimalistic settings of season 3, which they had in most of, if not all, of the villain's lairs. How would she have reacted to Batgirl? What would her team up with Cesar as the Joker have been like? Would they have still had a story about Catwoman wanting to be the best dressed woman if Julie was still in the role?
Mr Freeze appeared in the first two seasons, but was absent for the whole of season 3. Again, I can't imagine the character being in a season 3 episode. I wonder whether the reason for not having Mr Freeze back was that the character wouldn't have fitted into the whole third season format. The simple sets, the mostly singular episodes. And I wonder if they had, if Eli Wallach would have returned. Or would they have got a fourth actor to take on the role?
I'll leave it at that for now, but more queries' to come

