Referee Questions and processing time!

I am going to apply for citizenship for family (myself, wife and 3 year old kid)

For applications AN and MN, 2 referees require for myself, wife and my son
1. Professional person
2. British Citizen

Questions
1. For me and my wife application, can I use my friend as a Professional Referee who is Director of his limited company from last 6 month but he is having ILR with Indian nationality?

2. Can I use 2nd referee of my and my wife application who is British citizen for my son application also ? Or do I need different person with British nationality as a 2nd referee for my son?

3. Sending application with NSC , will reduce the processing time or it will take same time as postal ?

1. For me and my wife application, can I use my friend as a Professional Referee who is Director of his limited company from last 6 month but he is having ILR with Indian nationality?

If he is a Director/Manager/Personnel Officer of a VAT registered Company, that's OK. Doesn't need to be British.

2. Can I use 2nd referee of my and my wife application who is British citizen for my son application also ? Or do I need different person with British nationality as a 2nd referee for my son?

No problem using same British passport holder for all applications.

3. Sending application with NSC , will reduce the processing time or it will take same time as postal ?

Process time are similar (1-2 months for straight forward applications).

As a profession referee for child application- I have taken the sign of owner of nursery where he was going in past. Is it acceptable?
Because our GP is not willing sign as a referee and my son is too young and not going to school so teacher is out of question. We don’t know any social worker and minster of origin.
So I have taken the sign of lady who is running Nursery. Is it acceptable?

As a professional referee for child application- I have taken the sign of owner of nursery where he was going in past. Is it acceptable?
Because our GP is not willing sign as a referee and my son is too young and not going to school so teacher is out of question. We don’t know any social worker and minster of origin.
So I have taken the sign of lady who is running Nursery. Is it acceptable?

Any comments from Experts

It's just fine.