Hi Karen, You can sell within the next year and take advantage of both tax breaks:  the 250k (500k if you're married filing joint) gain exclusion along with the tax deferral provisions of 1031.  

By the end, we have a good idea if we want to get married.3.)

I am married with two children and two dogs. 

Best advice I can give anyone that wants to do this business right with flips, get a very good CPA that specializes in Real estate, this is very important, a lot of CPA's don't know crap about real estate investing, interview lots of them till you find the right one.If you buy and hold, you will set your self up very differently then if you are flipping only fyi.As for your 250k single and married, this from my knowledge only applies for your primary residence. 

. - we are a young married couple, about 30yrs old - our condo development was less than half finished when we bought in 2010, now the last units are built and I am told only 3 are left unsold.

This allowed us to begin to build equity while also saving money.I thought about buying a SFR and saving the cashflow but with getting married later in the year I couldn't live with my parents forever.  

Yes, I believe the current rule is still if you have lived in the home for 2 of the past 5 years up to 250k(single) or 500k(married) of gain is tax free.

I did call them and was able to verify previous addresses but was surprised that my report did not have those addresses or show alternate names of a tenant married 3 years ago.

You Can avoid tax altogether with a 1031 if you:do 1031’s until you die, never “sell”.The only way to Avoid/eliminate tax is if the house was your primary residence for two years, etc....avoid tax on gains up to $250k single, $500k married. 

Since then, we got engaged, purchased another SFH fixer upper, got married, renovated the SFH together, turned it over to a property manager, and have had successful income streams with both to date.