I bought a connecting ticket of Eastern Airlines from Shanghai.

1, like flying abroad at home, at the same airport, at the same terminal, it is generally recommended to take at least 3 hours. Forty-five minutes is definitely not enough, because check-in stops 45 minutes before the flight takes off. You have to go through customs. Who booked this ticket for you? Quite amateur. Generally speaking, it is difficult to change the time of international flights. Please contact China Eastern Airlines and see if I can help you advance that domestic flight.

2. When you say luggage goes directly to the second destination, the trade term is "luggage is directly hung". If you buy an internal flight of China Eastern Airlines, your luggage will hang directly. If it's not an internal flight, it's uncertain. When you need to check your luggage before taking off in China, discuss with the airport staff. If they can hang it for you, it's OK. If not, you can only handle it yourself. Generally speaking, it is easier to hang domestic A directly from abroad and domestic B from domestic A..

It depends on how late it is. Just like you, the interval is only 45 minutes. Once you miss the flight, you will not be responsible for accommodation, but you will be charged a rescheduling fee. If the previous flight of China Eastern Airlines was seriously delayed, so that the follow-up flight could not catch up, we can only negotiate with the airline manager on duty at the airport, and whether we can arrange accommodation depends on the on-site operation of the manager on duty.