Too broad a question to thoroughly answer. Homeowners may expense items an investor cannot, and vice versa, especially when the expenses we are talking about are related to ownership after the closing.
A good real estate attorney can save you money at the closing table by ensuring costs and expenses are allocated to buyer and seller, as well as credits.
it depends on what price range you are in. Currently Mortgage interest, real estate taxes and mortgage insurance if you make less than a certain amount. Hazard insurance or home owners association dues are not tax deductible. Let me know if I might be of help to you. Joanna 773-327-3580