My accountant was lazy, not well informed and provided bad advice.

Provide a detailed accounting of deductions, along with the invoices, to show you’re acting in good faith.

Holds the contractor accountable.

That is your denonimator.You also take the cash flow you get from rent minus all your expenses, so at end of day how much $ is in your bank account for the entire year.

Main goal of All In One heloc or 1st Lien Position Heloc:  Lower your daily average balance.Main Drawback: Rates are substantially higher than 60% of current 1st mortgage balances.If you are mostly living paycheck to paycheck and your money leaves your account as soon as it comes in to pay bills, this is not for you. 

I'm an accountant by trade.

If you don't have a great accountant which most are not. 

It may create a problem for you later if your bank discovers the account is owned by an LLC that no longer exists.

To put a relatively extreme scenario out there, if you offer 3% more than the next guy in cash (no bank debt) and provided a copy of a brokerage account statement showing the cash was available, I am certain you would get the deal.To echo Joshua's comments: how you are planning on financing the deal is hugely contingent on being awarded deals.  

Daniel,If its something you really like from all accounts, get with an inspector and property manager to give their thoughts on the area, condition of the property etc...