Hi Ren - As to the motivation/ambition of one GT person versus another, I'm not sure we as parents can have complete control over that. I think you see this many times in siblings, who are nurtured the same way and given the same opportunities. I think a lot of it has to do with the child's personality. Because you are more aware of some of the common pitfalls (lack of challenge in school, etc.), you can do something to try to avoid/prevent your child's future lack of ambition, and to try to find and encourage something that your child does have a passion for. But really there's only so much you can do, and I think it can be tricky to find the balance (what is pushing too hard? will there be repercussions/backlash?). And I think, with rare exceptions, most of us will have to wait until our children are a little older before we discover what they are passionate about.
As to the hot-housing versus giving your child opportunities issue, I often find myself reading things about hot-housing and saying, "Huh. Well I guess I did do alphabet flashcards with DS, and I did get him educational software before preschool." The difference is that DS wanted these things, or I got them because I knew he would like them. And he did! A more recent example: DS5 tried the Timez Attack free version (multiplication software) and begged me to get the full version. I told him I didn't have the money for that, so he paid for it with his own money.