One problem is that local markets and common business practices can vary wildly from area to area. 

I would recommend any real estate investor to have their real estate license even if there's no intent to practice as an agent for the mere fact the education will never go to waste from the course.

There's zero guarantee that any of these systems work and the practical side of me says that if there's a 100 people in the same city getting access to these "systems" then they should be bumping into each other if they are all going after the same local deals. 

If you have a sizeable estate, then a CPA who practices estate planning will be an added bonus.

As a matter of practice I have quarterly pest control set up on all my single families and townhouses.

Disclaimer: While I’m an attorney licensed to practice in PA, I’m not your attorney.

Instead of seeing patients they are talking to their employees their secretary for the third time because some grunt at the health insurance company is claiming a form is incomplete or a wrong code entered,etc.This is why many docs are getting bought out from private practice by the big guys.

Those guidelines detail practically every aspect of a loan and acceptable proof of loan eligibility.

Things like insulation practices and paint types have changed quite a bit over the years.

When making a journal entry, accounting practice is to use one JE (so as to anchor the JE number) and post to whatever T-accounts are necessary, meaning it's accepted to have multiple pairs of DB,CR entries in one JE.