I also loved seeing you yesterday. Your idea of massing Cupressus arizonica ‘Blue Ice’ is an interesting one. As a general rule this tree is thought to be best as an accent against a dark background to provide contrast. This is a lot of silver and makes a strong statement when massed. If seen against a white wall or a curtain of fog it tends to disappear. When in Sicily for two weeks last May I was particularly aware of the dark trunks below the silver foliage of old olive trees and the deep blue sky and sometimes red earth of a hillside above that. So, lots of contrast. If it were me, I would choose some cast-iron plant that is warm and colorful, but I am not you. Additionally, you are a great gardener and prefer a sophisticated look. I trust your eye to lead you correctly. The important thing is for you to be happy. The atmosphere you create needs to feed your soul and make you happy when you look at it.

Re: diseases, so far as I know ‘Blue Ice’ is subject to tip blight and not much else. So long as it gets adequate irrigation until established, good drainage and full sun that should not be too much of a problem. This is a very drought resistant tree and a stand-out in the landscape. I trust you to give it the care it needs and not to overwater once established. So from that point of view I think it’s a go!