Newbie Financing Advice

[Sean Harper]

Thinking about making the first purchase:

roughly $90K sale price

Plan to purchases with 100% Home Equity Loan 7% interest only for 12 months

Invest $20-30K in renovations (using 7% interest loan)

Anticipated value $150K

Then Refinance $90K with conventional mortgage before the 12 months are up.

It will cash flow $300 /month based upon current market rentals.

Question: Could I also consider selling property where I finance?  Would that make sense in this market?  Is that even allowed if I have a mortgage? Any tax implications, etc?  

Brand new to this process, thanks everyone!!