Here's the bottom line:
The fact that you're applying long before you need the passport puts you in a very advantageous position--one that more people should understand.
It allows you to submit the application without worrying about chasing after obscure information that's not at your fingertips. It is true that the question about where you're going isn't critical, and there's no reason to lie about not having determined a destination. Just put the truthful answer of "undetermined" on the form and everything will be fine.
And as to the question about the birthplace of your ex, the right answer is "unknown." Odds are overwhelming that this answer will be accepted, and if by some strange quirk it isn't, you will have time to do whatever legwork is necessary at that time, because you don't need the passport right away. To hedge the bet, it might be smart to circle the word "ex" on the application form.
There's no downside to being truthful and forthright.