If they are smoking outside and neighbors are not complaining of smell, they it should be a non-issue.   

State in the notice that there is a obvious difference between the smell of "old" smoke and fresh smoke.

There is very little specific guidance in the regs to this but there is a body of case law supporting this claim.  

There is a broken window and the smell of pet urine and feces is overpowering.  

Meet the tenant, interview them, see who tags along, did he/she respect the appointment time, did the park appropriately/respectful to neighbors, did they smell of smoke/alcohol/etc.2. 

Anything above this will be charged an excess body evacuation fee of $10 per flush.Sincerely,Your LandlordI'd really have questioned my plumber if he told me the issue was too many flushes.

Before doing so, the heating unit, while old (30 years), was functioning fine and often—he kept the house in the 70s without issue.When he got back, he turned the heat on, and it worked for a couple days before he relayed that there wasn’t any warm air coming through the vents and thought he smelled natural gas.My questions: How would you proceed, if you were in this situation?

You're starting to get an unrealistic number of bodies going through one bathroom.

He responded that they found a dead body in the house he was walking. 

The body of water that it is on is actually Curry Creek which opens up to Roberts Bay.