You are stating two different numbers here for mortgage balance($347k w/2 existing mortgages/$164k total ($147k+$17k DP). What I assume you are saying is there is a remaining of $147k on the first mortgage and a 2nd with the difference of $200kish?
From the initial numbers you are stating it may look like a solid opportunity, however I think you're missing some "real" expenses that will make this look not so attractive.
First off let me say that I do not know the Nashville market whatsoever, so hopefully someone that is can chime in and give you a better perspective. My experience has been that condos are not greatest of investments. In most markets their values are the last to appreciate and the first to fall during a crash (generally speaking). If your intent is to flip, you have a very small, specific buyer's pool as most want SFR.
If you flip, based on numbers provided ($380k retail comp and $347k existing mortgages) gives you little to no profit on the deal. A bare bones minimum transaction of this size w/no realtors will cost you 1.5-3% in fees (up to $11k), add in an additional 3% for realtor on selling side($11k), now your under a $10k profit (assuming you have no carrying costs, repairs/upgrades, mortgage payments, utilities...etc****DON"T ASSUME THAT!) Not a deal at all.
Cash flow/rental- My subj2 deals are always taking over the existing loan with no time frame set for me to refinance/cash out or otherwise. I take it over because the terms are favorable for the purpose of long term cash flow/rental income. My seller understands that and has no expectation of it being refinanced. There is no right or wrong. You can structure however you want. This just gives me the security that I don't have to come up with $XXX,XXX at a certain point in time. The other thing I would consider is how viable/strong is that $2800-3K/mo rental income? Is that inflated due to vacancy rate, economic conditions..etc? Does that location historically hold those values?
Make sure you calculate for expenses. Your monthly net income is not mortgage pmt/condo dues. You need to factor in a percentage for maintenance every month (paint/flooring/HVAC..etc), reserves for vacancies(3-8% if not more). All of these cutting down your net monthly.
Lastly, sub2 transactions are great, creative ways to acquire RE and get into the game, however there are some CYA steps you need to take regarding documentation and most importantly the due on sale clause. Every mortgage has them and yes the lender can call a loan. Regardless of the likelihood that they will is irrelevant because you just don't know. What you have to ask yourself are 2 things when doing a sub2:
1) Will I be able to sleep at night knowing that the lender(s) could potentially call a $347k note due?
2) Would you want 20 of these same properties w/same numbers?
Hope that helps.