See if there's a public tenant union who'd talk through the processes you need to follow. Local, large, universities are likely to have that sort of thing. They'll have people who deal with this sort of stupidity day in and day out. In some cases depending on state/local law, you can notify, get no response, fix on your dime, and withhold rent equal to the cost of the fix.
The owner's address shouldn't be problem -- it should be public record -- you need your local recorder of deeds office and the property address. You might even find your local municipality/county is tech savvy enough to have an online GIS application where you can type in an address and get ownership information online, including the address the property taxes bill to. There's your address. Note you may need some form of certified mail for the notice.