Sounds like you already have your answer that you need a permit, probably due to the balcony being a certain distance off the ground/ a safety concern. 

To ensure that your property meets all the necessary legal and safety standards, the most important next step you can take is to have a professional contractor or a home inspector take a look at your property.

If you were close, I would give him that 24 hour notice by forms of communication and even leave a letter at the door (If Possible) then show up with the police to protect your safety.

I have never had tenants decline to rent due to having to sign a lead paint disclosure,If you know there is lead paint, observe safety precautions when doing rehab work - the paint will not hunt you down and hurt you, you have to eat it or grind it up into dust and breathe it.

They might fear for their safety or the auctioneer might think of fleeing with it.....unlikely...but possible

I don't know many urban/inner city new construction residential projects where the Code doesn't require sprinklers for life safety.

Lack of training or safety guidelines heightens this concern.

Does this go with the territory or should I tell my renters to pound sand for anything beyond health/safety?

They work to eliminate smoke and cooking odors, to some degree, but be cognizant of the safety instructions! 

A door that doesn't open is probably a material defect (safety issue, if nothing else).