^Well, certainly -- given that Spock and Saavik later married in the novels, it's reasonable to expect them to have procreated.
Given the characters' ages by the time they married, I think having kids wouldn't really be a viable option by then.
Not necessarily. First of all, we're talking a half-human-half Vulcan, and a half-Vulcan- half-Romulan here, both species (which used to be one species) live centuries past the normal human life span, so having kids in their 100's is not impossible.
Plus, this is a FICTIONAL universe where humans have been shown live 90-odd years beyond what we live in reality, so anything can happen.