I would make a few changes to the list:
No hydrogen peroxide, iodine, spray on wound dressings --all of these products are harmful to the tissues and slow healing. Hydrogen peroxide is far from a good antibacterial cleaning agent too. (information presented at the 2006 AAEP convention)
I would also ensure that the vet's phone number is included in the first aid kit so you don't have to go digging for it in an emergency and a copy of a good equine first aid manual.
Here is are a couple of good links on first aid and when to call the vet, but be warned there are some graphic photos: http://www.acvs.org/AnimalOwners/Hea...undManagement/ http://www.acvs.org/AnimalOwners/Hea...uineFractures/