If I go with white for the vaulted ceiling, texture is critical! Beadboard and beams!!!... in this case it might work better with a horizontal line across the base of the triangle and the upper section white... the triangles just look so strange... otherwise this space is awesome and very similar to what I have in mind!
Love the white brick. We want a mantle with a brown reclaimed wood to coordinate with floor color. Built ins on side possibly a barn door to close in t.v. If possible. Shiplap painted white going up to ceiling. We do like the idea of using the color from island in kitchen on the sides of fireplace to connect both rooms. Accent wall if you must.