Question regarding refi

[Robert Dobbins]

Sorry if this is in the wrong location - I am trying to set myself up financially with your feedback on my current options. I currently own a home with a value of 170k - currently owe around $125k. I am 3.5 years into a 15 mortgage at a rate of 3.75. 

I will be moving early next year and renting this town home out in the Birmingham/Hoover area - I can get 1250 per month rent and expect to clear 1k per month after management and expenses. 

My question - what's more important - paying off this house and creating negative cash flow? My payment is 1350, so 350 per month to carry. OR refi to a 30 year with an expected payment of around 750 and creating a positive cash flow of $250?

I will be buying a home in the 300k range when I move - I also plan to looking for buy and hold properties in the 60-80k range in the near future. I am trying to ease my way into the investment world by renting out this home. Thoughts?