Waycrest Legacy Set procs and Disc Priests

I've been looking around, but can't find any post-early-beta information on these items. It's the set of ring and trinket from the Waycrest boss. I've got a couple questions about them.

1. Do we know the proc rate? I found that the DPS one ended up begin about 3% of my damage during a boss fight, which seems like a worthwhile amount.

2. Does the damage cause Atonement to heal?

They seem like a perfect set for disc priests, but I don't want to blindly assume that without knowing how they work.