"Diadem for 12 Stars" is not a Weakling ripoff. They are an obvious influence, but they are also influenced by early Opeth, Burzum etc. In general its a much more reflective, "spiritual" album than "Dead as Dreams". Check it out.
In general, I hear Weakling influence all over the US BM scene. Deafheaven come to mind immediately.
Also check out Dispirit, John Gossard's new blackend doom band if you haven't already.
Oh, and for Agalloch- Wolves in the Throne Room (again), Drudkh, Altar of Plagues, Dornenreich, Empyrium and Fen (though honestly I think Fen are boring as fuck- a lot of Agalloch fans like them).