Ambria

My husband is over in the US on a K 3 visa, but he has a son who is
finishing up college over there and does not want to come to the US until he
is finished. He still has 2 years to go on his degree there. (Manila,
Philippines)

My questions:

(1) He was 17 when we were married so I know he can get the K 4 visa, right?
He is 18 now.

(2) Is this hurting him by staying there until he finishes college? He will
be 209 close to 21 by the time he is finished.

(3) What forms do I need to file for him to start his K 4 visa? I-130?
I-129F? Same way that I did my spouse?

(4) If I start the process now and I know it will take a little while to
get approval and the actual K 4 visa, would he have to come right away? And
if there is a leeway of time - such as 6 months, can he come here and stay
for a few months and then go back to finish his schooling?

Any help appreciated on this!

Thanks!

Ambria