Really, really late to this game, but I figured I'd chime in.
Aquarius wrote:So, I'm wondering, what if, in a parallel universe somewhere, T'Pol turns left instead of right and declares the kalifee?
Truthfully, the only way I can see this happening is if T'Les realizes the enormity of her error - perhaps after the scene where she talks to Trip and admires him in her dead husband's clothes - and then promptly makes a beeline to T'Pol with the "you can't do this. You don't want to do this. I was wrong. Oh, and I'm also a Syrannite." Thus, T'Pol has an out.
Does Trip fight?
I'm of two minds: as someone who doesn't like Gary Stu Vulcans and as someone who saw Katra!Archer knocking Vulcan
commandos around with ease in the later Kir'Shara arc, I actually think that Trip could beat Koss. Sure, Trip would appear to be the underdog here, but in Trek (and most fiction) the underdog is invariably the winner, plus he's had to fight for his life a lot more recently than Koss. For that matter, I could actually see Koss backing down the instant he realizes that yes, Trip
is ready to do this and fight to the death for T'Pol. The big question is how does Trip react to this - as a human, I'd think that he'd see this entire thing as sheer barbarism and would be aghast at the notion that this is to the death. It really boils down to (IMO) how he perceives this - does he see the component of rape in these marriages that Honeybee referenced (and I kind of agree with)? If so, I suspect he's gonna unload of Koss without hesitation or compunction.
Does T'Pol, in a stroke of Girl Power badassery, battle Koss herself?
This could also be really cool, although we've unfortunately only seen her actually fight in the substandard "Marauders" where she tossed Klingons around. In this case, I think I'd go so far as to have her set the actual precedent that Torres uses in VOY - make it so that Vulcan law doesn't forbid the female from fighting her own battle ... its just that no one has ever done it before! And then, since Koss is a slightly out of shape architect, she whips his ass so thoroughly and completely that he's humiliated.
And what would the consequences be?
Here's where it gets ugly, though. With Koss kicked to the curb, he's not there in the later Vulcan arc to provide assistance, which means the Vulcan civil war is far more likely to turn into an actual war rather than the bloodless coup it was. T'Pol is also considered even more of a persona non grata on Vulcan, whether she had her human lover kick Koss' ass or did it herself. Starfleet would also have to be informed of this, especially if Trip fought Koss since, by Vulcan law, Tucker & T'Pol are now married, so that would likely lead to Trip's reassignment even sooner than canon (and would actually work better, IMO, because it is Outside Forces keeping them apart for a change rather than them acting like teenagers.)
And in the unlikely event that Trip fights Koss and is killed (unlikely because Trinneer is a main character whose name is in the opening credits, and the guy who played Koss is a guest star at best), T'Pol is gone from Starfleet and tensions between Earth and Vulcan deteriorate - Archer's dwindling Vulcan bigotry flares back up, likely brighter than before, and he's less likely to care about the Vulcan civil war.
Just my thoughts...