I have taken the depreciation deduction 4 of the 5 years, and I believe my tax basis is around $95-100k.  

@Levi Lewis I have my house hacking clients run numbers as though the property was a pure investment.

My understanding is that starting in 2018 a W-2 employee can no longer deduct  unreimbursed business expenses from their income. 

Honestly, based on what you described, I would just return the entire security deposit because - if challenged on any deductions - it sounds like you would have absolutely no way to prove the home wasn't in that condition when it was originally rented to the tenant.  

I will estimate the damage and deduct only the damage from security deposit.

Many condo associations do not budget enough for future expenses, then when something happens, they must levy special assessments on all the owners.

I would not get the deduction though on the tax I have to pay on the profit.  

In my case this deduction has offset my income from my properties and even adjusted my gross income.

Because its the basis in the structure that matters, you get to deduct the value of the land in making that determination. 

What do I need to do to still qualify for the tax deduction on the expenses?