1. Why doesn't Doaker tell Berniece that he has seen Sutter's ghost?
2. Why is Maretha now afraid to sleep upstairs?
3. What is Berniece doing as Avery knocks on the door?
4. Why doesn't Boy Willie have the man purchasing the piano come to pick it up?
5. How does Avery try to get rid of Sutter's ghost?
if these are the questions you're asking I think you're missing the bigger picture.
I saw ATL's production about 4 years ago. these are all really minor details. the play is more about a teetering connection to the past as modernity is creeping in.
(this kinda answers all of your questions, except 3)