The ceiling can be durock or greenboard, never regular drywall. 

If the agent is doing the marketing, finding the potential buyers and possibly working with other agents to help you secure a deal then I would still charge 2.5% for my listing services and 2.5% to any buyer's agent. 

I've shifted from trying to economize in everything in life to seeing that oftentimes it's well worth it to pay for the full service experience, no nickel-and-diming.

And if not then why should an investor use your service at all?

Obviously lots of factors play into this (market, debt service, etc.).

The arrangement works out fantastically, as all parties can now do what they're best at, and while we are separate entities, our services are integrated.  

Most MTRs in my area include utilities, but my California property has very high utility costs (PG&E - could easily be $1000/month with regular AC/heat use).

Florida’s high turnover in STRs means cleaning services are always in demand, while Texas’s suburban sprawl could keep a landscaping business busy year-round.

In fact, there may be other home service opportunities with quicker growth potential worth considering.Additionally, be aware that in Texas you’ll need a broker’s license, not just a real estate license, to operate a property management business.

Regular and transparent chitchats are the way to go.