Again, I proceeded to move forward with mold remediation only to have that buyer back out because "mold is scary."

If I don't go that route though, moving out in a year and renting out at market rates will still be a decent return.

If you move anything, walls, plumbing, electric, get a permit.

I actually have done personally exactly what you're describing - HELOC on primary residence, use that to purchase new primary, move into new primary and rent the previous home(4 times in 5 years).

If your contract states the percentage you get from future bookings...usually it's 10%...take that and have the owner move all bookings to their listing.If you don't have a contract, I'm not sure what to suggest except to split ways peaceable, even if you lose money.

I am planning on moving to the Tampa/St.

You can move on from there and purchase a SFH if you don't like sharing a MF. 

I do believe that with some TLC this house can appraise for 50k higher by the time I move out as well as cash flow.

Do you think I should move forward given the returns once it is rented or is the short term loses too much? 

Hello,I recently graduated from college and am moving up to Nashville for work.