Your mortgage has nothing to do with your taxes.Here is a very rough starting point, however the actual calculation will involve more details:1.

Anything involving a service animal and ADA should be directly consulting an attorney on the matter as every case is different. 

I am also involved in management at one of the largest STR property management firms in Cashiers.

Be very careful who you take advice from online, you should get involved with a local attorney and a local realtor.

Plus new folks do a very poor job of screening the buyer for Ability To Repay (ATR) which involves pulling full doc and calculating the borrowers DTI, honest income, honest debt payments, prior debt payment histor (FICO) etc etc.Plus shockingly (or shocking to sellers) if you bought this investment house, fixed it, then are selling with financing you are selling "inventory" and y9ou owe taxes on the gain in the year of sale, you are NOT able to use installment sale to spread out paying taxes. 

Without my wife's direct involvement, I think some of our homes would have struggled to stay afloat.   

I've selected Collin, Denton, and Grayson counties as my investment focus.My goals involve investing in small multifamily properties and long-term rentals.

@Geoff Engel If you don't want to be a landlord but still want to be involved with investing you could be a private money lender for flips or in partnerships and bring the money to the deal.

There is no seasoning requirement involved since the property isn't a short sale and it isn't someone buying REO from a bank with a seasoning requirement.

And this does not even involve business or real estate!