Discuss COC return, run a financial analysis for him and a performance chart showing the ROR after multiple properties have been acquired and cashed-out... good luck.

In our market, you can self manage, with all the associated work, and out perform the LTR income.  

Have you performed an amortization analysis to see when your net earnings after depreciation starts to become positive?

If there's a hole, it may be a red flag.b) sensitivity analysis: I examine all the assumptions, and make sure I can live with the worst case scenarios.c) "Stall and see": if they are getting money over multiple years, and there is no penalty for investing later, I would usually wait so I get some real performance data, versus having to look at theoretical pro forma information.d) Recession stress test: I will not invest in anything, until I subject it to recession level stress and see if I can live with the result.

I originally thought this would be a low cost route to documenting the issues and alerting others.

If not what is the best way to reduce my tax payment to what it was originally and is it possible to prevent increases in the future?

Originated a note for $1,100,000.  

In order to collect 3% in the scenario you presented, you'd need to amend your original buyer agreement.If your commission is 2.5% and the seller is paying 2%, you can structure the additional .5% into the purchase price. i.e.

Short-Term Rental (STR) Options: If an Airbnb on your street is performing well, consider converting your property into a short-term rental.

Give it a try for two consecutive projects and see how you perform by project 3..... you will be surprised how such a small tweak to your budget can impact the overall project performance.