It is traditional to have your maid of honour and best man as the god parents of your first child. As they supported you in your marriage so too should they support you with your family. If this covers your desire to have your best friend then you should ahve the best man and you can explain it to your family that way. Tell them that family will be considered for future children, just to keep them off your back.

We had our baptism with 3 others on the first Sunday after new year,in a catholic church, I'm not sure as to the sharing the baptism, but I would ask at the church how many have booked in for that day and how many they would allow to book in.

It isn't that bad to share your baptism as you have the "function" after for the private time.