#2. T'Pol was clearly into the whole mom role, so even if the guy (whom she 'mated' with) had made such offer, I can't see what would be so damn repulsive. I don't even see it as distasteful.
If my child suddenly died and my husband offered, that day or anytime in the near future, to make another baby, I'd be terribly upset.
That's what's repulsive. If instead they left the idea of possible additional hybrids alone, I think the moment would've been more touching.
The moment between Trip and T'Pol was one of loss, shared loss. By Trip offering to sire another child, he really trampled on a nice moment and a shared understanding of their loss.