If you have a tax company and real estate that is paid off, you should have no problems getting an unsecured line of credit.

Also, is it the first person who submits an application and passes the background/credit check who I move forward with as the tenant to fill the unit?

Your final considerations are Credit Cards or a HELOC but do their benefits carefully and pay them off in time. 

If so, then you can't deduct the mortgage interest, but you can deduct a portion of property tax.And you will have some other expenses such as Internet and maybe mobile phone costs - but you will need to separate out "personal use" vs. business use.

Examples: A guy with hotels who used business /personal credit cards for free flights, a guy doing private investing/hard money lending, and last month was a guy who told the story of a 12+ property deal spanning 2 states and 1 primary residence of the seller.  

(Avoid big banks, try local banks, credit unions, or mortgage brokers.) 

The panel on the wall was wired for electric and an internet connection so they can put a TV there if they want or just hang a picture or mirror if that is their thing. 

I've been using Local Banks and credit unions (Portfolio lenders). 

"I hope I won't get audited" is not a strategy for success.Secondly, I will caution that there is information on the internet about "partnering with your IRA" such that a joint venture is setup. 

I'm going thru the credentialing process and they're currently asking me what Fair Credit reporting act (FCRA) system I will be using for decision making.