As the owner of 87.5% of the units in that building, you should have a big say in how things are run in that building.Without knowing my numbers, my intuition is that it would probably make sense to acquire the last unit if posisble.However to know for sure, I would  run a comparison analysis between keeping the units separately or pricing the building as a one multifamily.I would use the statements from the HOA to know precisely what my expenses would be.

Buying the property under value, buying the property which is poorly managed and under performing, buying a property that needs work and or can have some value added by changing the layout or number of units.

Does anyone have experience with renting such a layout? 

Whereas older housing stock can be more difficult to renovate - especially when it once was a large single family that has been spliced into apartments.If I was to build a Multi-Family property from the ground up, I could control the lay out of the units, where the housing systems were located and their path to and from the basement, I could construct panels to access shower fixtures etc.

If the counter layout just has straight sides (no corners), you can buy 8' wide sections of basic laminate counters for under $100 in stock at a lot of stores and cut them to the length you need.

Regarding your question, intuitively you'd think a bank would only care about NOI/cap rate/equity at purchase vs when you refinance, but I may be wrong, hopefully others who have been through the refinance process can share their wisdom.

Go through the what if szenario's and lay out startegies that will lower your exposure.

I just closed and was given a check in the amount of both tenants deposits.Right away you want to call and transfer any utilities that the previous owner was paying, as well as call and set up a time to introduce yourself to them, as well as lay out clear guidelines and expectations as to what to expect with you as the new owner, ie. where and when to send payment, contact info and info on what to do if there are any issues that need to be addressed.I just closed on a new duplex and acquired tenants, i called right away and started service for water and garbage for the tenants, as well as met with them in person, I showed up with a copy of their current lease agreement for them to have as a refresher, a basic rental application for them to fill out to make sure i had the most current information about employment, tenants, contact info, as well as had them make a list of concerns and things that need repair. 

Is there a website which will layout the Tax Liens for sale or was that just a pipe dream to get easy money from those seeking knowledge? 

Hire a RE agent if necessary, get a RE attorney to lay  out the process in each state you plan to do business.