I would be living there to satisfy the terms of the FHA loan I would need, so my actual cashflow would be ~0 for a year.My Question This property is in a small college town and I'm wondering how I would find out my vacancy rate as well as what I might be able to charge after some rehab work.

Last year my long-term girlfriend bought a owner occupied duplex that we've been renovating with the intent of using the equity to buy a second property.Unfortunately, our relationship has soured (but maintains a good friend/working relationship) and she wants to be bought out.Issues:-I'm not on the deed (yet)-I'm not on the mortgage (5yr balloon due in 4)-I have no significant cash for a down payment but good credit and income.Goal:-Pay off current mortgage-Repay her initial down payment-I assume/restructure to get the duplex and mortgage-Pull out any remaining equity for a 50/50 split.

Your best approach should be to remain as a renter in your new area nd get a really good first hand feel for the market before you invest.

if you have assets, the lender you walked away from is going to come after them to cover the remaining loan balance any way.  

They won't necessarily remove it from your credit report, but they will report it as "satisfied" instead of having a judgement.Keep working on it and don't let it bring you down. 

Since the 1st lease and original security deposit was taken, many different tenants have moved in and out - each paying the outgoing roommate for their part of the security deposit so the LL wouldn't have to get involved and they'd always remain "whole" (we were instructed to do so by LL).

Compared to multi-family buildings in the same price range with 15-20 units that remain profitable with 3-4 vacancies, which are generally straightforward to fill, offices look more risky in almost every way.Attracted to offices having lower maintenance tenants, but that doesn't seem worth the riskier investment dynamics. 

If you feel that you're still not satisfied with what's left, you can also skim coat the floor with a flooring patch and let it dry.

If there was $500K in gain and you took 100K in boot you would pay tax on 100K but would shelter the tax on the remaining 400K.  

We are currently on our 2nd buy and hold property (thx to @Brandon Turner, @Joshua Dorkin for the podcasts I listen to daily and the motivation to take action).We currently own a duplex purchased using a HELOC for the 20% down,closing costs ($20,200)  and a private money lender for the remaining 60k @ 12%.