Pay mortgage principal and then take equity loan

[Antony Peter]

I have a mortgage towards my primary residence. I have paid off around 20% of my loan, and my current interest rate is 4.5%. I have some cash enough to pay for a down payment on a condo (around 20%) and rent it out. I have been looking to refinance the mortgage for the primary residence. I am on a work permit, and I need to consider the scenario of losing the visa and returning back to my home country, in which case I may have to sell the house / rent it out
My options are 

1. 30 Yr mortgage with a rate of 3.875%. In case if I have to rent my primary residence, the estimated rent per month will barely cover the monthly payment. I can put some extra down payment to get my monthly payment down

2. 15 Yr mortgage with a rate of 3%. I have to put significant extra down payment to get my rent to cover monthly payment. Should I get a 15 Yr mortgage with extra down payment? If so, when I buy a condo for rental is it advisable to get equity loan against my primary residence?