Assuming when you say "$3900/mo in rental income" you mean cash flow.That means it will take you about 13 years of rental income to equal the $500k in equity you have now. 

I'm looking to get a 3 unit multi family home in or close to Boston MA. my question is is it realistic with a income of 75k-100k to be able to get a 800k loan?

When it's sold it will be taxed as capital gains tax and may also have some unrecaptured depreciation which is capped at 25% and  recaptured depreciation as well which can be up to your ordinary income tax rate.

Investment Info:Building a Fix and Flip/Wholesale Active Income Arm of Our Business.Routinely have 5-10 active flips/wholesale deals under management/in process.

Could not find much online so figured I would turn to BP.

You have to report all other types of income to WV besides Wages and Salaries.Therefore, yes, you would report the WV Rental income to WV.

To answer your question, you can use AirDNA or another short-term-rental income analyzing website or software.

Net investment income tax= 3.8%I was aware of the Long term capital gains tax, but I was surprised to find out about the Depreciation Recapture and the Net investment income tax. 

your w2 income tax burden will NOW be lowered. 

Any tax knowledge of if people doing this strategy are able to take the losses from the cost seg study (on the ADU) to offset their W2 income?