One thing I would add to #2 is that if you do not have shoes on your horse, you could consider learning how to do trims yourself. There are a number of clinics provided in every state that will teach you how to correctly trim a hoof. This is something that I have been considering, but have not done. I do know a fair number of experienced horse people do their own trims.
I agree with hotreddon that the wording on #3 should be changed. Also, maybe include what it means to lease a horse or half lease. In particular, if you are new to horse ownership, how this may be a good way to get introduced to having a horse and the costs.
Here is another idea to save money. If you own a well schooled horse and board at a stable that gives lessons you may be able to reduce your costs by letting your horse be used for lessons. This is a good option only if you trust the trainer to manage the horse correctly.