In addition, the gas bills have shut off notices and are not being paid. (3 units are occupied and utilities are all paid by owner).

Additionally, are there any other factors I should be considering when purchasing a duplex or triplex?

We're based in Tampa and, in addition to personally investing, I own a mortgage company that provides financing for tons of investors.

Whether the seller was open to a buyer commission or not, I wouldn't put an additional cost into any personal purchase.  

Many lenders also impose additional requirements such as owner-occupancy, and/or that one lender make all of the institutional loans in the building.- Valuation: The variety of financing products available as individual tenant in common loans remains limited, and the terms are generally less favorable than either apartment building loans or condominium loans.

When evaluating a property management company, it's important to look beyond just the management fee and consider the full scope of services and costs involved.For example, at our company, we charge a 10% monthly management fee, a $250 lease renewal fee (unless it’s a takeover tenant, which requires additional effort to establish a strong relationship - because usually people are changing pm companies for a reason), and the first month’s rent as a leasing fee.

You pay your agent at closing (think of it as an additional closing cost) Depending of the situation and of these options can be used by you and your agent to negotiate with the seller.

Just one additional option.  

You should always require them to add you to their policy as "additional insured" or "additional interest" and you will be notified if they cancel or change their policy.

This is due to bonus depreciation which allows taxpayers to deduct 40% of qualifying property costs in the first year, in addition to regular depreciation for new construction and improvement.