I have to say $500 for a laser in this condition is very steep. Please tell me you didn't pay that much....well, here are some random thoughts.
The good news - the mast step looks solid. Those can be a pain to repair. The easy way to tell is to fill it up with water, and see if it drains out....
I was going to suggest simply painting, but having taken a closer look at your photos it looks like re-glassing will be needed. The foam core is so thin I would not bother to cut it out; glassing over it should be fine. You probably need a couple of layers of cloth. A good preparation will be key. Spend solid time up front ensuring the surface is totally clean, major voids are filled (if necessary with a few layers of fibreglass for a big hole). Dig out any loose/weak 'bondo' work. Where things are screwed in - cleats, fairleads, etc consider expoxying reinforcement - such as plywood - to give the screws something to bite in to.
Your process looks good; you may want to have a helper to mix up the resin, so you can put it on in smaller areas, roll out bubbles, add the next section without stopping to remake resin. REmember you need a special roller or plastic scraper to squeeze most of the epoxy out of the cloth - the cloth should not be dry (white and shiny), but neither should there be pools of excess epoxy! One big sheet of cloth could be a lot to handle, you may want to think of adding smaller, more manageable sections (with a reasonable overlap.
I would suggest a number of layers of thinner sheets.
Fibreglass is awesome stuff, and pretty easy to handle, so take it slow. Remember, don't add more than 2-3 layers in one go, or it will get hot and distort. When dry, you can use a variety of compounds to fill and fair. Personally I like a 2-part fairing compound for final (detailed) fairing. I would use epoxy filler for medium-size problems like holes, and cloth for larger depressions or structural problems.
In my experience the areas which get the most abuse are the bow (bumping into things), the painter "cleat" (which looks ripped out and badly replaced in the photos), and the decks on either side of the cockpit where you sit. The stern - where the rope traveler lies - I have not seen as a problem area. The most common failure area, as previously mentioned, is the mast step.
I notice you have a few items of hardware apparently missing; the hiking strap is one you will almost certainly need! So check you have solid screw-holes for that.