Operations- tenants refusals, either cull them before they get to you by requiring autopay as an example, document on their application why you refused them, make sure your facilities are maintained properly and no safety hazards exist, etcLLC.

Use an operating account for income and expenses, a reserve account for maintenance and taxes, and a high-yield savings account (HYSA) like Capital One's 4% APY for idle funds awaiting reinvestment.

One thing I would mention though - doing STR just to save taxes often leaves you operationally unstable or too detached from the management to be successful.

Simply document everything you do and create your own Standard Operating Procedures (SOPs).

Quote from @Carlos Lopes: Gross income doesn't matter.This is the number most people post, and it's 92.7% useless.What you need is NET income, meaning the money left over after all expenses, and that should include a dollar amount for your personal time spent operating the business. 

Also, depending on your long term goals, transitioning part of your portfolio into more passive investments might help reduce operational stress while keeping your equity working for you.

A lot of investors have great success when they start with a deal that has lighter value-add potential and use that deal to learn how to operate a rehab.

What tools have worked best for you to streamline operations? 

You're planning to operate this as a STR/MTR.

That's really cool and I suspect my dad mentioned our operation out in KC to him.