The details of the incident remain unclear, but they intentionally granted access to someone who subsequently stole major appliances.

Use your HELOC to purchase the duplex outright for $118K.Your brother’s $50K down payment can immediately go toward reducing your HELOC balance, leaving a remaining balance of $68K.Create a formal lease-to-own agreement with your brother.

The only other advice that I would give is if your primary motivation is to save on taxes, don't do it.

IE motivate them for money. 

As long as he is making his payments according to our contract, he remains legally responsible.

With $330/m in cash flow, unless you have sufficient reserves set aside those funds should remain as liquid as possible in the event of repairs or cap ex.

If one tenant moves out, the property remains cash-flow positive.

If one tenant moves out, the property remains cash-flow positive. 

I know I will be back eventually but if I remain in the US for many more years the tax implications are a bit scary. 

A line of credit is adjustable rate with interest only payments that will have a "draw" period usually of 3-5 years for investment properties (usually 10 years for primary home) then will amortize over the remaining term after the draw period.