They can take full sun, but a little shade might be better in your area. Yes to the peat moss, and Miracid. Here I water once a week, usually, and alternate Miracid and Miracle gro. I would plant it. I wouldn't leave it in the pot.
I think Evan has a Lion King opening soon. In my opinion it's one of the loveliest JIs, and has great stature.
A little history on Lion King. Ensata Gardens hybridized it, and has sold it to Walters Gardens, the leading wholesaler in the country. So it will be on the market. Walters Gardens is also currently trialling one of my favorite siberians, Seneca Midnight Blues to buy from and sell for Dana Borglum. So for the present, any Lion King on the marker should be true to name as Walters doesn't make mistakes. But once it gets floating around and propagated by everyone and their distant relative, it will be mixed up in commerce like the Dutch ones are.