Good on you painting on the hoof oil or hoof grease whatever they call that particular one. You will notice when his feet are cracked or jagged they need trimming, we get our horses feet done every 6-8 weeks. My horses with shoes get done more often as they overgrow their shoes.
I think that your boy will be happy to have horses close by, they can depressed on their own as they are herd animals. So long as he has some friends he will feel safe. Sounds like you are enjoying him which is great! If he eats too much of your tree you can paint sump oil on them, as tree bark in horses bellies doesnt work very well....

