As you are in New York it would be a good idea to consult a local real estate attorney before entering into any commitments. It would also be good idea to contact the building department in the borough the property is located as well as consulting some local engineers and licensed contracting/renovating companies to get their feedback.
Very few lenders will approve a escrow holdback in today's market, so that is probably not going to be an option. However, the one exception may be repairs that cannot be made due to weather conditions; such as a roof repair in New York in December (LOL!). If there is any possibility that you will need mortgage financing, I would make sure you discuss your question with your mortgage professional prior to making any offers on the property.