Also, plan for your TV to be about three feet lower in its eventual setting -- it should be at your eye level when you're seated, and right now it's more like standing height, which will send you to an orthopedist soon.

That T.V is hung way too high the center of the screen should beat eye level when you are seated and IMO the T.V centered on the wall like now makes more sense than centered under the peak it then allows you to have equal size cabinets on either side . Have you checked out the Besta system from Ikea it works really well in this sort of setting

I would center the tv and fireplace on the wall space between the wall and door. Not install them to the ceiling.

Here is a current design we did. Notice how the built in's on the side do not go all the way to the ceiling? Also notice the TV height.

Woodside Updated Traditional Home · More Info

An electric fireplace? What size is it? I hope it's wider than the TV.

I would off set the fireplace and put the TV beside it.