( I have moved to another city) If I simply report to the authority against the fake property manager, what kind of consequence will that cost the fake property manager?

Shutting the water supply to toilet will just cut supply to the tank.

He's simply a hired gun and carries no liability or makes no decisions.

They paid him a living wage and cut him in on a percentage of profits when house sold.

And it depends on how much trim is being removed, doors to cut around etc.

What is your objective, to be a top agent, simply to use the license for your own investments, or a bit of both?

Nope, that appears to be a pretty clear cut case of fraud unless he fully disclosed everything to the lenders.

(I'm specifically speaking about 80+ year old properties)Generally speaking, I feel a rehab will simply clean up a place to make it more desirable to buyers and slightly increase it's value.

What if one of them cuts off a finger with a saw and want you to pay for it?

Then just assign it to your end buyer and you both take your cuts at sale.