So if a client is at the 37% rate a $10,000 study would only really cost $6,300, and that doesn't even include the state tax deduction if applicable. 

Although it may not be located in CA, it is still advisable to investigate if there are any rent control laws applicable to the county or state, as Theresa mentioned.

It appears quickbooks and a separate loan manager application or rent manager have the “lender” feature I am looking for.

Not really a loophole, just correct application of the law!

While I understand your concern about potential grey areas in certain industries, it's crucial to differentiate between businesses based on their individual practices and compliance standards.In our case, I want to assure you that we prioritize transparency, integrity, and compliance with all applicable regulations.

(Can I use the estimated cash flow of the house as proof of income for mortgage applications?)

To mitigate concerns of placing a bad tenant, set your application guidelines as strict as you need to feel comfortable, and STICK TO THOSE GUIDELINES.

The guide is ambiguous as to whether or not that applies as an exception to CMX-1 zoning, or is applicable to CMX-2/3 zoning.

So do I send the corporate addenum with the application or after the approval?

Perform the same task in each app to ensure a fair comparison.Load a property with pictures and details.Market that property.See what your marketing looks like from the public's perspective.Submit a fake application to see how easy the process is.Run a credit/screening report on yourself.Enter a maintenance request, assign a vendor, and attach a fake invoice.Enter charges to the tenant's ledger.Enter recurring charges and automatic late fees.Sign documents electronically.Run owner reports.After testing a few apps, one should clearly stand out.