Many reasons here, but the most common is they went into deal with short term floating rate debt at a market peak.

There are options to take a loan against your 401k which I had success with but profit margins after tax were not worth the hassle of the project. 

Not having done your 2023 return will in all likelihood 'hurt' you somewhat in the short term because lenders will want to see it.  

The short answer is No, you don't need it.

If I had a rough checklist or something I could follow, I truly believe I would find success.

Lately, I’ve been encountering some challenges with municipalities imposing new rules and restrictions that impact my properties and operations.I’m interested in learning how others have successfully addressed these issues.

BRRR, short term rental, mid term, long term, house hack, etc???

Our priorities in terms of market is there needs to be- anticipated economic growth (lots of tech companies are moving into Columbus),- prices need to allow us to buy in all cash (400k or less, ideally up to 300k),- we want the area to be safe (when looking into places like Dayton, OH or Memphis, TN for instance it looks like all our boxes are checked on paper, numbers wise but we realized quickly there are a lot of unsafe areas and we could have the potential for problem tenants)- yearly expenses to be relatively low (i.e. we are avoiding NYC and the tri state area, California, etc. for having extremely high taxes).Is our initial analysis on the right track for Columbus?

Cap Rate is a term only relevant to commercial properties.  

https://www.biggerpockets.com/blog/brrrr-loans-what-are-the-...Short-Term Rental Loans: What Are the Options and How Do DSCR Loans Stack Up?