I also need someone to help me understand the process for applying Department of Housing and Community Development multifamily rental financing programs.

@Josh Oden there is a real estate department at Texas A&M that tracks real estate data that may be helpful to you. 

that will trigger all kinds of other departments and taxing authorities. 

In all these cases, I called their respective cities to see if the properties could be legally converted into multi-fam, to which the zoning department said, basically, "no" for various reasons.

You might call the fire department's business office.

Fortunately I am just outside of the boundaries of the historic district and do not have HOA, Historic district, or any other governing body (Besides of course City of Houston permitting department) to answer to. 

You get the name of someone at a bank (rather than a department) and your initial call or email is "I got your name from Jane Doe who recommended I call you based on work you've done with her clients before". 

Agents are sales department and claims are claims department.

A call to your local building department should get you at least a general answer - and a good feeling whether you'll likely have to do the work or if you might be able get by without it.

I did send an email to Air BnB and I'm waiting to hear back from a friend in the police department as well.