RE: how to repair gel coat
I cannot answer your question, but I CAN tell you what NOT to do.
I busted the cowl on my H9 Katana with a chicken stick; the engine kicked back hard and flung the stick right into the cowl leading edge.
I repaired the break from the inside with some medium cloth, then sanded the outside smooth, feathering the edges, and shot some color Lustrekote rattle can spray paint. I wasn't interested in a pristine repair, just removing the eye-sore aspect.
Said paint got up under the edges of the gel coat and bubbled. Looks like hell now.