For Pic1, where exactly are these holes located? we need to know if it is a load bearing part of the boat.

Clean out the hole of loose fiberglass with a circular file. Most of the time you can make a backing plate of pressure treated wood that fits through the hole but is longer than the hole. You drill a small hole in the center of it (or use a push pin) and put a string (or strong thread) through it. slip the backing plate it in the the hole, pull it back with the string so it is flush with the inside of the hole. then you glue it there with super glue (you only need it to stay there long enough for the marine-tex to dry). Cut the string as short as possible oncee the glue dries. Finally, fill it up with marine-tex.

Pic 2 if you push hard on the deck where the crack is, does it give at all?

Pic number three. remove the crappy repair with a dremel or loose bits and fill it with marine tex. once dry sand it flush