A toilet was loose.  

And should  I leave my Agency I will loose my current listings.

This tells me that submetering might drive all tenants out (almost all units on the rent roll are $25-125 below average rents, including the competition) and that even if I underprice the competition by $25-$40 or so, I'll likely loose to them (as the winter heating bill will easily eat that up. 

The thing is, I don't want to loose a month's rent and even though by law her actions will make her liable for damages (lost rent) and lawyer fees. 

The smart kid who doesn't want to loose all of his hard earned marbles has to play somewhere else.

True, you will end up loosing some properties that you could have offer more and still be good deals...but that's the game.

Additionally, you loose control over the quality and aesthetics of any repair or upgrade.With a lease - option, the tenant is a tenant until s/he/they exercise the option and place a downpayment.

So a leaking toilet looses a few thousand gallons in a month.

You never signed the contract with the PM so you are not bound to them. 

I will go as far as saying any business that doesn't use online social media as their main tool right now is bound to regret it once major corporations and Fortune 500 companies start shifting their HUGE ad budgets towards the same thing.