as to paying the forth quarter state estimate in December. 1) you have to be able to itemize otherwise paying early produces no federal tax benefit. 2) you tax deduction on schedule A for all other taxes (including previous state estimates and any balnce due for the prior year paid in the current year must be less than $10,000 ($5,000 married filing separate) otherwise again you get no federal tax benefit becuase under current tax law that's the limit for schedule A taxes.
