As others have stated, your fit & finish goals should be guided by whether you plan to:1) Rent: tenants don't always take care of a property, so you want to use lower-grade materials and workmanship.2) Flip: higher quality on workmanship and materials is usually required.Regardless, you always want to "Maintain to the Neighborhood".

All rents you get from this property has to go back into the SDIRA but if you get a 20 year mortgage (that the rent can cover) and can pay the rental off by age 65 you will have turned that $90K into several hundred thousand’s of paid off real estate.

What type of loan is this?

There are other ways to use OPM and not be as risky about it.What you should do is leverage this money at 80% LTV and put 20% of your own money into the deals.

Yes, this strategy is possible!

Guessing you used an uninsured, cheap handyman?

When looking at discounting properties to find a deal, I tend to lean into what the seller is looking for when I know I'm holding. 

Is there something I'm not taking into consideration?

Quote from @Scott Trench: What I have seen in my own life was this..- Working a W2 as a firefighter, posting and consuming content- Leaving my W2 to dive deep into real estate investing and working as an agent... and still watching/posting content all while business was ok - Deleting social media apps (one have one on my phone that I use 10 minutes or less a day), diving deep into building my business and skills which have drastically increased due to pure focus and increasing my business significantly- moral of the story... focus on the things you need to do in business (dollar productive activities) and life experiences while reducing consumption will increase your success  

This is a two-sided beast.