I've been at forums where people got upset if you started a new thread when there was a similar one buried deep in the forums from a year or more back. I don't see any harm in continuing with an old thread, reviving an old conversation.
Funny enough, I just watched STII and am about to watch STIII when I took a little break to go online, and found this.
I never doubted for a second that Spock and Saavik had wild pon farr sex on Genesis.
I have read the Pandora books and the Vulcan's Forge and Vulcan's Heart books, in that order. So I saw Spock as Saavik's father figure - which can easily be seen as the reason for Saavik's grief. The later romance came off kind of creepy because of that.
I think Spock going thru pon farr on Genesis pretty much proves it's biological, which is what I thought. A psychological reason for pon farr wouldn't have all Vulcans having a psychological breakdown in the same pattern, some could go much longer, some much less. I don't recall anything about Romulans having pon farr, I assume that's a Vulcan think, much like their telepathic powers. It's a shame that Saavik being half Romulan wasn't developed in the movies, as that's an interesting aspect of her background. Saavik in STII definitely shows more emotion than we've ever seen from a Vulcan not under some kind of influence. Saavik is really likeable and interesting, and I think was and is generally pretty popular. I think the movies at that time could've benefited from having her around. She certainly wouldn't have made STV any worse.
I do think Saavik being pregnant by Spock would've been an interesting twist. It's a shame that they wrote out Saavik so casually, I'd have liked to have seen her in the other movies, but I'm glad that they gave her role to Valeris, as I don't think that story suited Saavik. But then my opinion is drawn from novels and years of distance, I guess our opinion on Saavik would be pretty different if she'd had Valeris's story.
I'd think with the age difference between Spock and Saavik it'll be a long time, if ever, before she shows up in the new universe.