Why fight over the tree? 

Also had to fight city utility over me being responsible for tenant's water bill.

Did landlords in NY sue the city or use other means (other than burning the buildings) to fight rent control? 

Is the original person on the lease still in business/alive maybe it could not be assigned -another legal thing to fight. 

Said he and the neighbor fought over garbage cans and it turned into a gun fight. 

If you feel there's a chance the tenant will fight you, I recommend you hire a professional company so you have an invoice and a third-party witness.

As for that threat of a law suit, I would throw it right back at them and mention that they failed to disclose an environmental hazard that they either knew about or should have known about, and I am sure that my lawyer will consider this little oversight an attempt to defraud me, and I will happy enjoy that court fight. 

She failed to respond to the notice of review from CMHA to file an appeal to fight the rent increase so the decision could not be overturned. 

I find it funny when the rich people of Barton Hills, Hyde Park, etc whine about affordability while at the same time fighting tooth-and-nail against multi-family in their neighborhood, as they tear down their own house to put up some huge ugly mcmansion (and pay the fines to cut down a few "heritage" trees along the way).

Over the years, there have been many fights about who is financially responsible for what and who has to pay for repairs/maintain tenants.