Does replaying a level brings more coins for the next levels?

I can't get expert on the 4th place.

Does replaying a level better brings more coins for upgrades?
I wish doing so will get me more coins for more upgrades and be able to get expert on the 4th place.

Yes, you can replay levels to increase your coins.

If you are having trouble getting expert on level 4, are you clicking ahead so that she goes immediately to the next task?

You can also keep clicking while she is stacking shelves to make her work a bit faster.

Hope this helps