The interest rate is 2.375% so I am having a hard time letting go of the excellent rate.My question is: To scale from here, should I sell it and buy a fourplex as a house hack? 

Hello Satish- the greater Banner Elk area does have a lot going for it and the right property should provide you excellent income and a potential nice getaway spot. 

For the tracker, I would just have a simple Excel sheet without generic entries 

Based on my research, this PM company is highly reputable and provides excellent service.

Excellent so far! 

The most important thing is to know the details of your local program like the back of your hand, then look for loopholes.Just to give you and the other BP'ers a deeper handle on why some TDR programs work and some don't, I just uploaded an excellent study on the topic to my FilePlace at http://www.biggerpockets.com/files/user/ChrisNewma...

He is a very conservative investor and gives excellent advice which helped me a lot.

Your advice about understanding the underlying accounting and how the numbers are generated is an excellent point—I can see how that would help me identify any gaps or inaccuracies in the financials.I also really appreciate the insight on how T-12s differ based on the number of units.

Oklahoma is excellent for flipping, as well as for buying and holding. 

Excellent feedback, thank you @Kevin Sobilo