I would be arriving at PEK from USA , holding an Indian Passport, and booked through Air China

My itinerary would: be IAD(Washington DC, USA)--> PEK(Beijing)---> Delhi(India). Both leg of journey through Air china. I see the connection timings are 2 hours and 1.5 hours each both ways
My questions:
1. Will that be sufficient timing to catch connecting flight ?Both legs of journey are operated by Air china.
2. air china usually operates from T3 ?
3. Will Air China help in transferring luggage to the onward flight both times ?

Regards,
Shinjinee