With that being said, what steps should I take prior to submitting an offer to protect myself and my investment?

You'll spend a lot of time scouting neighborhoods and getting a feel for the market. 

One other note, regarding the title of the post....we do have an umbrella policy in place as a layer of protection for the flips and other BRRR we did.

The good news is that if this guy is not protecting your money properly, there are always professional real estate investors who will work with you. 

You spend $50.000 to buy and fix up a duplex.

I don't want to be spending money on a list using useless filters.

Even if the market conditions changed negatively but not drastically, the contractor is willing to absorb their share of the profits in order to protect the investor's share? 

This is definitely a seller's market, but if you have her set you up with MLS alerts, you can spend time analyzing deals that fit your criteria without any pressure.

Spend a year fixing it up and do other jobs/flips if you have the time/money on the side.

I currently read a book plus half a dozen podcast episodes a week... which means it's time to spend more time talking to real investors and seeing real deals.As you can see by the icon, I'm a falconer; I train wild hawks.