Best of luck on the investment journey, feel free to reach out if I can be of any assistance! 

Always best to research mortgage companies/brokerages for things like compensation, availability of training, assistance on files since you are new, and if they teach you how to constantly get business 

We live in California at the moment and I have W2 job and my wife a small online business.

Hey Matthew,A lot has changed since you posted this but I also lived in New England and now live in St Pete.

The typical clients that seek out cost segregation studies include:Real estate companies that buy and sell multiple properties each year.Individuals with a portfolio containing investment properties including apartment buildings, multi-family homes and even single residences.Franchise owners with properties that are similar to one another such as assisted living facilities, storage facilities and golf courses.Business owners of hotels, food facilities, shopping centers, restaurants or manufacturing plants.It depends on the type of property, but generally 15-45% of the building’s costs can be classified into assets with a shorter life.

I really believe that we live in a time where all the information you need to do just about anything is available for free online.

You'll want to enlist a CPA on this to assist you- Repeating the above for Cancun, since it's a vacation destination already, I'd almost guarantee you that you cannot write it off 100%In regards to travel, it's also important to remember that even if everything is used 100% for business, the IRS classifies business expenses being valid if they're "ordinary and necessary".

I’m based out of state so would be looking for a company that could assist with day-to-day issues as well as securing tenants.

Another option is to put 2-3 inches of spray foam insulation then batt under that, it will assist with stopping some of the air transfer and seal it off as well.I would also check the windows in those rooms and whcih way do they face.

@John Cooper when you or someone you care about is living in the home it is important to be extra vigilant in choosing tenants.