RE: Tree stands
The area that I hunt has many tree stands setup year round and even though I did not put up all of them I know everyone that hunts the woods that I do and we have an agreement that no one takes another persons stand site for the first week of season after that if you're not in it it is free game.
That has been worked out that way for years though - I wouldn't go onto public land or property that I did not have permission to be on and just take someones stand though.