MN1 in process valid PBS Visa- Urgent Trabel

I and my wife got ILR on Nov 2013 and then we applied for our son's registration using MN1 in Nov 13. I applied using NCS service. He is born in UK and currently have PBS Dependant visa due to expire on MAY 15.

MN1 is taking ages and now we have an urgent need to travel back to our home country. Now, I have couple of questions related to that:

1)Can he back to UK on his PBS VISA which will expire on May 2015? I am asking this becoz i have seen mix information regarding main applicant visa status change lead to void PBS Dependant VISA. I will appreciate if you provide any link to support.

2)Can i apply for his British passport in UK once i received the registration certificate while he is outisde UK?

Plz advise thanks

1) Yes.
2) No. A passport application must be made from the country the applicant is present.

Thank you very much for your reply.

1) Yes. Could you please provide any link of UKBA regarding this matter.

Thank Jambo

Can you please provide me link regarding the above matter?

As you mentioned that my son can re-enter in UK on his PBS Depandant visa due to expire in May 2015