I deduct taxes and water bill , and insurance , which are high in that area. 

@Aaron MoayedIf you dig far enough into IRC Sec 469 and the related regs, you'll find this:Treas Reg Sec §1.469-1(f)(4)Carryover of disallowed deductions and credits(i)In generalIn the case of an activity of a taxpayer with respect to which any deductions or credits are disallowed for a taxable year under § 1.469-1T(f)(2) or (f)(3) (the loss activity)—(A) The disallowed deductions or credits is allocated among the taxpayer's activities for the succeeding taxable year in a manner that reasonably reflects the extent to which each activity continues the loss activity; and(B) The disallowed deductions or credits allocated to an activity under paragraph (f)(4)(i)(A) of this section shall be treated as deductions or credits from the activity for the succeeding taxable year.When reading tax law, what is not mentioned is just as important as what is mentioned.This Treasury Reg section, taken together with the IRC Sec 469 helps establish there is no definite carryover period for passive activity losses -- as opposed to NOL carryover.

Interest to the bank does get a tax deduction, but most of it is still 'rent'.

I would add to #2, that Multifamily apartments have an added tax advantage over ALL other commercial real estate, and that is the the depreciation schedule is on a 27.5 year basis, instead of 39 years like all other commercial properties.This allow a larger depreciation deduction each year, whether you use cost segregation to accelerate that, or not.

Especially since the tenant has been such an excellent tenant and was very understanding of some unexpected problems we had while they were living there (unless we find other major problems that we need to deduct).

I want to fire him an deduct my expenses to fix all this from his last payment.

The loan monthly payments will be deducted from your pay automatically each month.

Then deduct that from her first months rent owed?

Can I deduct interest rate, HOA fee, and other cost to maintain the house from my tax?

You cannot deduct repairs on a personal use asset.