With the exception of building a trailer on the property (these are hard to finance), this sounds like a good plan AND if you are using it for your business AND your business pays more than 50% of the rent (if you have more than 1 tenant), then this is a more financeable property in the eyes of banks and credit unions as it would be consider a commercial "owner-occupied" property. 

Use gap funding (credit lines, partners) for the down payment.

You need to build your credit.

However, I noticed that as a Costco member, they also offer HVAC services, including the same product line (Lennox), along with a 10% Costco Shop Card if you go through them.Has anyone here used Costco for their HVAC needs?

If the property were owner-occupied, would I only receive credit for one rental unit's income, while the non-conforming basement income wouldn't count?

If you have nothing, and make nothing, you declare bankruptcy, wreck your credit and try to go back to renting.

do not use a line of credit for a down payment. 

BTW there is a free trial and the Starter monthly plan is $119.It also allows you to search through consumer information such as property owner "credit worthiness," Credit card usage, buying power, age, language, family members in the house, and many other fields that are above and beyond property characteristics, which is unique.

I wasn’t late on one credit card payment.

Was the brownfield credits distributed in year 4?