Can I leave out or substitute for the peppers? Wife doesn't do hot.

Perhaps a bit of paprika for pepper flavor without the heat.

How about roasted red bell pepper, sweet cherry peppers or piquillo peppers to give it some dimension? I'm in your wife's camp about spicy and usually swap out these peppers to suit my taste.

I agree with June, no substitute needed, though a small amount of Aleppo pepper could work well. I love Aleppo for its sweet, gentle heat; unless you use a large amount, the Aleppo would add flavor but not much spiciness.

I'm not Amanda, but I often leave out hot peppers if I'm cooking for someone who does not appreciate them. It's never ruined a recipe yet. :) I wouldn't think you'd need to substitute anything for them.