When I enter property tax into TurboTax, it splits it between business and personal BUT considers the personal portion as RE Taxes for a 'vacation' home. Does it matter?
Yes.
I haven't yet found a way to override it.
Override for what purpose? The program is doing things correctly. For a property not rented the whole year, if you have more than 15 days of personal use, (I think it's 14 days) then you have a vacation rental, and the personal use days count against you for what expenses you can deduct on the SCH E. More details in IRS Publication 527 Chapter 5 (page 17) at https://www.irs.gov/pub/irs-pdf/p527.pdf
