I plan to manage the properties myself until it conflicts with my regular job.I would appreciate any advice on these markets to ensure success and connect with local investors.    

Woah 13.85% even on an investment property is super high...I got a heloc at a 7.25% (this is variable with the market as with any HELOC) for an investment property.Talk to your local credit union.

How valuable is this location in that market? 

Any advice on starting out on this in the Houston or Katy market?  

Tremont is an excellent area with really high market rents and super high demand.  5000+ sq ft. is huge too, congratulations!

I would always lean towards markets that are landlord-friendly. 

Any brokerage can be the right fit for you so long as you commit to taking initiative and putting in the work.By 'work', I mean income-producing activities (lead generation and follow-up) i.e. cold calling, door-knocking, contacting your sphere of influence, networking, hosting open houses, running online advertising, marketing (paper or online), or anything else that will get you in front of prospective clients.My first broker rarely answered my phone calls and by the time she responded, I'd often already have the answer I was looking for.

I have a small team but work 3 different markets.

Hopefully we will be managing a handful of other STRs in the same market in the future.

In Cleveland you can find below market rental ready duplexes that require minor repairs (keep in mind that discounted properties come with their own challenges).