Going to and transiting through China for the first time in December.

Flying YYZ-PVG-PEK all on China Eastern on one ticket. Do I need to pickup bags in PVG and re-check them? Also I only have 2 hours in PVG. I've read about people freaking out over how 3 hours is already tight. I've done 2 hour connections at other places around the world with no issues, is 2 hours really not enough at PVG?

Also flying DPS-PVG-REP on China Eastern on one ticket. Flight lands in PVG at 7:15AM and the flight for REP does not leave until 10:20PM. Would like to go into the city to explore. Will I need to retrieve luggage in PVG and check it back in. If I do need to pick up my luggage will MU allow me to check it in on the REP flight that early in the morning or is it safer to just pay for luggage storage?

Thanks in advance.