Just my personal opinion - get a mentor or a person who already has good experience running STR business, preferably in your area (but not 100% required). 

I'm a small business owner and my partner has a corporate job. 

I opened a business checking account with Regions.

How about using SDIRAs not to hold assets but to operate businesses?

Bigger Pockets is a great place to find a real estate tax accountant.A good real estate accountant can save you thousands of dollars by leveraging entity selection and formation, tax deductions, cost segregations, bonus depreciation and tax planning.I recommend finding an accountant who specializes in real estate taxation, business taxation, financial planning and tax planning.You may want to consider working with your accountant remotely to expand your options.I would also recommend looking for a accountant willing to work with you throughout the year.

Seems like a pretty straightforward way to do business.

Try and join a few local Facebook pages and connect with locals who are in the house hacking business. 

Your taxes are none of the ex wife's business and this would seem to address your concerns.I would also put her on notice that future requests for financial discovery will be two-way and if a discrepancy is seen in the other direction you will seek support from her.

Hello all, I'm working on trying to grow my rental business and looking at different avenues for funding. 

You are complaining after four months of trying in a brand new business that you didn't know anything about?