HELOC to buy rental property, cash-out or not, tax benefits

[Raj Ga]

Questions:

1. If I use HELOC to buy property outright and turn around do cash-out refi on rental property, would be interest rate will be .25 higher?

2. Has any one use HELOC to buy property outright and use rent to pay off the HELOC, if I know I will sell the rental property in next 10 years before I need to start paying principals?

3. Do we get tax benefits on interest payment on HELOC being it a rental property?