Since your score will be based on your household income, you can't bulldoze an existing house or sell any of the furniture from a house you buy. You don't have to buy an empty lot, but if you buy a furnished house, you can't sell anything in the house.
You can't bulldoze any community lots.
Regarding cheats, look at the general rules and the ones for this challenge.
You don't have to use a spreadsheet.