Which hours count for the 750 required to be a real estate professional?

[Samuel Joseph Hamilton]

So I have an acquaintance that has a substantial amount of real estate (managed by a property manager), and they have a lot of ordinary income from various sources, resulting in a high income tax each year. This friend is interested in trying to take over management of their real estate to qualify as a real estate professional to the IRS in order to be able to write off losses from real estate against their ordinary income, including IRA withdrawals or conversions to a Roth IRA.

This friend is retired, so there is no problem reaching the requirement that over half of your working hours have to be in real estate, and if he was the property manager it seems he should be able to pass the material participation requirement by being the person most involved in the running of the real estate. 

The requirement I wonder about is the "750 hours in real properties or trades that the person materially participates in" requirement. I've read many articles about this but it seems everyone has different opinions on what counts. Obviously things like renovation, property management, talking to a banker for a loan on your own properties, etc. all count. But would being a real estate broker or sales agent count? Would it only count whenever he is the broker for his own real estate acquisitions, or could he just be a real estate broker in general for 750 hours and qualify? 

If it has to be 750 hours all spent on running your own real estate I'm not sure how anyone that is not doing lots of renovations or manages 50+ properties could ever qualify for this!

Thanks in advance for any advice!