You should absolutely buy properties and then rent them out so that you are building equity and taking advantage of tax deductions such as depreciation that only an owner can get.

From what I've read and heard, the biggest advantage of BRRRR is creating forced appreciation for when you get it appraised, to pull out more money then you put in.

We have thought about finding a partner to invest,  but my wife is not fully convinced that a partner is a good choice because neither of us know how to get a contract for that type of thing written up and she doesn't want to be taken advantage of. 

Your $100k is your 25% down payment and hold back some initial reserves and closing costs...find the market that meets your criteria for a C-class value-add MF property, build your team (starting with an agent), and pull the trigger...long-term buy and hold...drop all profits back into renovating units and forcing rents higher...take advantage of your equity in 4-5 years and buy another one.

Here is the advantage of the variable rate to you vs your banker, lets say 7 yrs in rates drop to 2.5%, guess what you can call your lender and refinance your loan and get that 2.5% rate locked in for 5 years. 

The advantage there is that SFH are far more plentiful, and there is not (quite) as much competition for them as the duplexes.  

You probably want to sync with an Ohio CPA as well to confirm tax treatment advantages.

I'm wondering if I should continue renting an apartment until things cool down or if it would be worthwhile to take advantage of a low interest rate + start building equity in a property. 

Additionally, like was said above, FHA loans are especially advantageous when trying to buy a 2-4 unit property as you will still only have to put 3.5% down.

By way of example, single-member limited liability companies or any investment in an entity in which an individual is a director or officer could no longer be held in an IRA.IRAs holding any of the above investments would lose all of the tax advantages previously available to the IRA.