Before engaging in a transaction like this speak with a company/professional who set this up for you, you do not want to make a mistake here, it will be very costly. 

I am nothing but professional when I speak to them, and she is incredibly verbally abrasive and refuses to let me talk, then hangs up on me.  

I would suggest speaking to your landlord and gaining written consent that it was okay to find a new roommate.

The example they've set thus far speaks much more loudly than any info you'd find.I don't know the rules in TX, but I would look into whether you're able to increase the security deposit when you start a new lease with an existing tenant.

So be sure to speak with qualified tax expert and understand the impact of it before deciding to move forward. 

@Alison Mercer without knowing the exact area of the house I am only speaking from my experience investing in Ohio.  

Legally speaking, if you sign the form for dual representation, you may get an impartial agent, but even that is unlikely.

Cannot speak for the cat. lol

Go speak with your portfolio lender, and ask them if they would re-fi with a balloon cap not to exceed 8%.

I'd be happy to connect to speak more.Best of luck!