I know I will have to find my own inspection company(s) and the like but is there anything else I need to think about?

If you haven't already, I'd recommend getting cost segregation study quotes from multiple companies and then taking those quotes back to your CPA to discuss if you would be able to benefit from the study.

I had some problems with the management company not advertising promotions at all and likely over-screening potential tenants.

I think if I were to sell it now I could get around $600k, maybe just below.My company is moving my family and I to NYC and will be covering our housing (rent) for at least a year.

For those that have used one these larger companies - have you ever got a second opinion from some other firms after signing up?

I own a PM company in nearby Tampa, and probably about 80% of our clients are out state and even out of country. 

Volkswagen Scout Brand investing $11M in Detroit, 200 new jobshttps://www.teslarati.com/volkswagen-scout-11-million-detroit-investment/Hotel Added to Hudson Site, total over $1.4Bhttps://www.detroitnews.com/story/business/2023/11/02/hudsons-site-hotel-plans-move-ahead-as-city-issues-permit/71426631007/Detroit west side Dexter Neighborhood Receives $21.5Mhttps://www.clickondetroit.com/news/local/2023/11/01/neighborhood-on-detroits-west-side-receives-more-than-215m-in-investments/Norway’s Nel Hydron investing $400M, 517 new jobshttps://businessfacilities.com/nel-hydrogen-will-build-400m-gigafactory-in-southeast-michigan#:~:text=In%20Southeast%20Michigan-,Nel%20Hydrogen%20Will%20Build%20%24400M%20Gigafactory%20In%20Southeast%20Michigan,green%20hydrogen%20using%20electrolyzer%20technology.Chase invests $200M in Detroithttps://www.axios.com/2023/09/28/detroit-rebound-jp-morgan-investmentGilbert Foundation invests $439M in Detroithttps://www.henryfordmsu.org/news/september-2023/gilbert-family-foundation-announces-nick-gilbert-neurofibromatosis-research-instituteBollinger Motors investing $44M, 237 new jobshttps://michauto.org/bollinger-motors-plans-44m-metro-detroit-investment/New Detroit Developments to Be Excited Abouthttps://www.metrotimes.com/detroit/15-new-detroit-developments-to-be-excited-about-photos/Slideshow/32734721/32735392BorgWarner Investing $20.6M, 186 new jobshttps://www.crainsdetroit.com/auto-suppliers/borgwarner-invest-206-million-create-186-jobs3 International Companies Choose Detroithttps://www.detroitregionalpartnership.com/international-investment-comes-to-detroit-region/District Detroit $1.5B Development, 12,000 temp jobs, 6,000 new jobshttps://www.detroitnews.com/story/business/2022/11/15/district-detroit-1-5b-development-to-include-housing-retail-hotels/69649853007/6 New Residential Developments in Detroithttps://detroitisit.com/6-new-residential-developments-in-detroit-to-know-about/$2.5B New Center by Henry Ford Health, Pistons owner and Michigan State Universityhttps://www.clickondetroit.com/news/local/2023/02/08/incredible-investment-in-our-city-25b-detroit-neighborhood-redevelopment-to-begin-in-2024/$300M Huntington Place Renovations & New Detroit Hotel https://www.crainsdetroit.com/real-estate/huntington-place-renovations-new-hotel-deal-reached

@Travis Kumarseems like something you need to talk to your agent/ attorney / title company about

Does anyone have any referrals as to insured companies that can rehab the property as well as keep it secure while rehabbing?

The funds leave your 401k or traditional IRA directly to the SDIRA company.