From your description most of the trees and plants were destined to leave your garden anyway (donated or sold). That was the intent of the prior owner.
So, you cannot let them all stay. Not enough room.
The real question is: In what manner do you want them to leave your garden?
Have a neighborhood digging party. Flag all the ones you are getting rid of with flagging tape, and invite people to come dig up and remove what they want that is flagged. You will get to know everyone in the neighborhood that way.
I have never heard of someone refusing to cut lawn before, though. That sounds totally bizarre. Guy does not sound like a professional. Buy a mower.
PS - You cannot really sell any of your garden plants without being state inspected as a licensed nursery.
PPS - I am assuming it is a very very small town. What bank employee has an hour to waste talking about a house when they should be working? And why wont your neighbors talk to you when you ask them specific questions?
