You can learn how to repair hull holes in fiberglass boats here: http://www.boatus.com/boattech/casey/17.htm
Fiberglass is actually very flammable.
Fiberglass.
Depending on the material used for the Hull, there are Gel Gloss Paints used for Fiberglass and composite boats and very good Acrylic Enamels and Urethane for sealed wood.
Most modern sailboat hulls are made from fiberglass or a fiberglass type, it's strong and light, relatively cheap (or one of the cheaper options for hull materials) and can be commonly found wherever you cruise around the world.
A planing hull.
at least 50 years
The main body of the boat.
the hull helps keep the boat stable, if there was no hull, the boat would go in different directions
No. Once fiberglass is set, it cannot be altered.
Cracks in the hull
get on a plane quicker
A single hull boat has only one hull, which is the standard for boats. Catamarans have two, or twin hulls.