Can a property improvement under $2500 be written off in the year it occurs, even if the expense happens before a renter is put into the property?

Most investors here look to have the rent cover the mortgage and some.While the principal on the mortgage is not an expense, the interest, property taxes and insurance are deductible expenses.

@John Franczyk on the tax front, there is no expense you cant write off, or business tax benefit that cant be taken weather you are an LLC or a sole proprietor historically, its all pass through anyway, for example if you have a HELOC on your personal home, and use the money for business purposes, the interest and expenses are deductible as a  business expense. at the end of the day it makes no difference, unless you are avoiding  SE and filing as an S-Corp, but thats for active income, not passive.

The IRS filing info says "If the only member of the LLC is not an individual, the LLC income and expenses are reported on the owner/member's tax return."

Put the minimal down, and find properties where the income from rents would cover mortgage and other expenses (and hopefully provide additional profit each month).

Taxes at $6017 and owner states operating expenses at $13,470 and total expenses @ $19,487 with net operating income at $72,253. 

The interest is truly an expense. 

Other than the AC, there is no other large expenses hanging over us.

One expense you might consider is the time it takes to field calls from owners who have property you don't want.

Self Storage Purchase Price: $169kCurrent: Annual Income: $15,180Annual Expenses: $3,487Insurance: $1,636Property Taxes: $1,177Electricity: $762NOI: $11,693Year 1 Pro Forma:Annual Income: $17,460Annual Expenses: $4,720Insurance: $1,220Property Taxes: $1,375Electricity: $762Grounds Maintenance: $1,400NOI: $12,74038 Unit Breakdown (currently under market rents by $2-8/unit).