Don't be surprised if there AREN'T any board minutes to review. Hence, you may not be able to confirm anything. And yes, the Sponsor very well could be controlling the board, because s/he may BE, in essence, the board. While it's a pain in the ass, that's basically the natural progression in buildings like this... which is why as soon as the ratio flips to shareholder majority, it will be up to you and the intelligent people you meet to start investigating, and then beginning the evolution. Read your By-Laws (which may be unfortunately vague) to see how & when the voting in of a new board is expected to happen and hold the sponsor's feet to the fire. There are on-line sources to guide you, as well as the NYS AG's office.

If you decide to take a chance and purchase in this building (or anywhere you purchase), make sure you have your own excellent real estate agent (do not share the sponsor's) and your own real estate attorney. Get all agreements in writing. If it's a gut-renovated unit, look it over very carefully and request any fixes agreed to in writing. Do not rely on their good will, or in how nice they are. That all goes out the window when money is involved. If they promise you anything, get it in writing. Good luck.