Can a Mamachari be fitted with an 11 speed 52-36T crankset and FD? I would like to upgrade this bike with a better and faster crankset, 52-36T, but I'm confused if my planned setup will be compatible with the bike I have. I have consulted in our local bike shop and they said that a Dura-Ace crank would fit but the FD will have a hard time or impossible fitting considering the top tube design of the bike. 

I'm not really sure if he saw my bottom bracket being really old. Might there be any modern bottom bracket to fit it at all?

Edit: Finally found an enlightening link
https://bike.bikegremlin.com/1297/bicycle-front-derailleur-compatibility/
If you want to fit a modern crank you'll need to be able to fit a compatible bottom bracket. Right now you have a threaded bottom bracket shell with a non-cartridge bottom bracket. If the threads are ISO/English standard and the width is standard threaded BB road width (68mm) then you can fit an external bearing road BB and road crank. The BB shell looks a bit wide though.

The other major issue is clearance between the chainstay and large chainrings that the frame was not designed for