Thank you for sharing your thoughts. I have to say I'm a relatively conservative person and not willing to bear many debts.
I think it's feasible for us to buy a house in the nearby good school district, and hold two houses at the same time. If we do so, we have to extend our current loan from 15 yrs to 30yrs. I have not decided yet if we want to take such a LT debt.
Your suggestion is definitely helpful! I read some of your posts, many good ideas.