I need an authoritative or 99% complete list of addresses and their lat/lng in NYC. Is this data inside open streetmap? If so where?
In general you can get some hints to your aim at
https://help.openstreetmap.org/questions/2680/can-i-produce-a-database-of-addresses-from-osm-data or
https://help.openstreetmap.org/questions/12388/best-way-to-get-all-cities-of-a-specific-area or
https://help.openstreetmap.org/questions/9816/the-best-way-to-extract-street-list or
https://help.openstreetmap.org/questions/15132/export-german-zip-codes-with-geographic-position
you can also search at http://help.osm.org for keywords like export, list, address, csv or similar.
If you need prefessional help in this task, you can also consult any company listed at http://wiki.openstreetmap.org/wiki/Commercial_OSM_Software_and_Services
BUT:
no one can garantuee that the addr: Objects in a certain area of the world are 90% or more or less.
Unfortunately, I believe that house numbers in NYC nowhere near 99% complete in OSM yet. 
Street names may be at that level of completion, but there are still a lot of numbers missing as far as I can tell. (I’m not involved with the local community there, though.)