Welcome! I don't know about the loads on the new flight but I can help with the other questions. You will need a buddy pass for each person...including the lap-child. The baby will only pay 10% of the adult buddy pass fare, but still neeeds its own pass. Also, you will only be able to standby for coach because of the kids. Only kids over age 8 can standby for first and business class. Parents are required to be seated in the same cabin as kids.

One last note...you will need a Russian Visa if you are an American citizen which will run you $100 USD for each person...not sure about the baby. Check out the russian embassy in Washington's website.

Happy travels!