But now I realize that while I was busy learning about analyzing the numbers and what to expect, I didn't learn about the LLC aspect!  

You can certainly find plenty of loans out there that can work on the scenario you described above but expectations might need to be a little different right now.

She took the liberty of moving out early, and is now claiming that she won't pay and expects the full deposit back.

We have about half of the price of the building, but not the whole amount; we're also not excited about using all of our cash for purchasing, since we expected to put a percentage down on this one and be able to buy another building also. 

What guests will not forgive is not setting the right expectations.

I expect to be ready to buy only in several months.

Does it make economic sense to buy a house with private sewerage with the expectation that it will command a high value if changed to the city sewerage? 

However we were pretty close to expected expense per door post closing.

Hilaire are you expecting a lot of appreciation?

., I think you nailed it: the TENANT BASE in Boston has low expectations, so even low quality buildings fetch great returns.