Yes, and there's lots of OOC moments for most of the crew in S3. Most likely because so many BTS creatives like Coon, Justman, Fontana, and others had left the show by that point.
Yeah, that works for me. I just can't buy that Spock was genuinely attracted to TEI's Romulan Commander at any point. She's easily fooled throughout the entire episode, and intelligence should be requirement #1 for a Spock love interest. There's just no way he's going to fall for someone that stupid.
I wonder if another part of Roddenberry's reasoning was he realized Chapel's scenes would be less likely to be cut if she was consistently sharing the screen with Mr. Spock. TOS was a pretty disposable character, but if she was sharing scenes with the breakout star of the show, that keeps Majel happy and out of Roddenberry's hair.