There's a few other considerations regarding how the baseboard, door jambs and cabinets relate to the existing floor but if the surface of the concrete is not acceptable, you might want to consider tile.  

If both entities exist and both conducted business in the form of money or contracts or titles, then I believe both need to file taxes.

Vacancy is typically related to community economics, the property class-{a,b,c,d} and how well you market & manage the existing tenants.

As an investor you have less stress, you don't have to where a yellow or blue blazer, no need to look for the balloon in the air and don't have to pay dues, attend meetings, meet a quota, do a coop with agents who take part of your commissionJust think no floor duty, no driving customers around to look at houses,  waste your time and gas. sap your energy and leaving you only to buy a property from their brother in law who just get their licenseOh YES, the freedom to make all the money your are worth, no need  for the hassle of finding listings, prospecting, floor duty.......oh the freedom that an investor has, oh the pleasure of sleeping late, making creative offers, doing subject to existing financing, delayed settlements, collecting assignment fees.....oh the sweet freedom of cash flow and free time.

But I am a glutton for punishment, so it only wet my appetite so I kept going onto other deals.To answer Mike's question - I went on to get my Brokers Lic. and took over an existing office as the operations manager, first thing I did was revamp the rental department.

At the very worst, the 2 existing homes should be neutral, until you refi them.

The demand for rentals is high across the nation so no reason exists to compromise.

I've been hearing and reading about buying subject to the existing financing.

Sorry to rain on you, but IMO, hearing, "ONLY, ALL, Never" ignores other choices as if they don't exist, which clearly just aint so, and rings my bell (sorry) - - when there are just consequences to some that 'usually' are unpleasant. 

You are the bane of my existence.