Yes, it is NOT a personal deduction, but will be an expense against the income...on either your schedule C or I, depending on how your handling the property 9as a business or as an investment).

No.

An investment interest calculator will calculate the amount of interest that you will have to pay on an investment on a home, car, or other type of big expense.

You can deduct investment interest up to the amount of net investment income received. You report this on Schedule A using Form 4952 as a back-up computation. Defining net investment income can get a bit tricky. In general, it includes gross income from investment property (such as interest, dividends, short-term capital gains, and elected long-term capital gains), less any investment expenses (which might include expenses for investment publications and similar things).

Interest charged is normally an expense - in that it is a deduction from an account. Deferring payment of the interest, means the money that would have been paid is still in the account - making it an asset.