Nina gave you some great information. To sum up:
Heating: Natural gas powered hot water baseboard
Roof: 20 years left side/5 years right side
Garage: It would depend on the property lines and the setback/encroachment codes as to whether or not you can make it a two-car garage to the side. However, you would very likely make it two-cars deep. A qualified contractor would be the only one to say for sure.
I live within walking distance to that house on Hetcheltown and would be happy to show it to you at your convenience. I am a Certified Buyer Representative and in case you didn't know, my services come at no cost to the buyer on any listed property. I am paid from the seller's closing costs to represent you. If this house isn't for you, I'm happy to help you search for the right one.
I work every day from 8am to 8pm. I look forward to hearing from you.
NYS Licensed Real Estate Salesperson
Certified Buyer Representative
Bliss Properties of NY