You can have return visa before completion of 1 year stay outside the country by paying Qr:500. This return visa is valid for 14 days.There is no fine system and you dont need to pay before 6 months. This can be paid anytime before completion of 1 year but you must bring your family before 14 days(before expiry of return visa).
I am not sure about that 3rd party can do this on behalf of you since I have done myself.
You need make PP and a visa for your kid as well.

Hope this will be helpful.