Have you checked if there's a peony gardening society near you? You'd be able to see the blooms at display tables, and talk to people about them. You're doing a great job with your peonies--and yes, peonies really can die, at least out here and pretty easily, out here. Some started out as much weaker divisions for me, and some of it is just sloppy clay soil that stays wet all winter. But also, they get a blight that looks like the foliage got burnt.