I'd just get your numbers locked down as far as operating costs.

You can’t screen it out, you can only build operating modes to streamline the cost of turnover.

A bit of unsolicited advice that you will thank me for later: make sure that you and your boyfriend each have your own holding LLC's and then buy the investment properties as a JV with each LLC owning 50% of the operating LLC.

You will also need to write up an operating agreement for each LLC and follow the legal process to keep them in good order.

In the lower class neighborhoods, it's imperative for the landlord to never get comfortable and try to run operations on auto-pilot.

Managing your own properties is fine but in TX if you open it up to others you need to operate under a broker’s license.  

.#5 Practice, Practice, PracticeWalkthrough potential rehab properties (or find properties virtually online) and practice creating detailed scopes of work, quantifying repairs and estimating rehab costs for the projects.Once you get some experience estimating costs or get a few rehabs under your belt, you will be able derive your own 'formula' that you can use to quickly estimate costs and analyze deals.  

Most turnkey operators seem to recommend min $100k purchase price and $800/mo. rent to avoid taking on properties with deferred maintenance filled with tenants that are more trouble than they’re worth.

I'm interested in fixer-uppers, C-class assets in a B-class area because I'd like to operate using the BRRRR strategy.

$1000 / month for coin operated laundry?