Apologies for the book you are about to read...

My energy to complete several of the small unfinished projects from our whole house reno three years ago is coming in waves. I've found a DR chandelier (hooray!) and am now ready to tackle the fireplace walls. We installed a see-through fireplace on a free-standing wall separating the living and family rooms with plans to tile up to mantles. Thanks to input from Oldbat2be on a past thread on my kitchen backsplash (another project yet to be completed), we decided on live edge black walnut mantles to echo the nearby kitchen's black walnut island top, with large-format carrara tiles to match the carrara perimeter counters right next to fireplace.

I have several questions. First, some photos of the space. (Excuse party prep mess in the first one with fireplace mock ups.)

1.TILES. It was tricky to find something that matched my counters. I think this works. Do you think this is the right tile? (Note that these aren't the actual size, only samples representative of the marble coloring.)

2. MANTLES. We picked a wide black walnut board with live edges on both sides and had it sliced down the middle to create two mirrored mantles. A section of one:

Here's where I start to battle my usual design aesthetic. I like very simple, clean lines. Simple. From my research I found a three common treatments for free-standing wall fireplaces with mantles.

A. Shorter mantle with only painted drywall. No tile or stone. (Not a see through here.) This would be ok, except I wanted a little something more.

B. Shorter mantle with whole wall covered in stone. I don't want to tile floor to ceiling. Too much hard surface for my small space.

C. Headbanger mantles. Thanks to mocking up mantles running across the whole wall, we know that running the mantles right to the edge doesn't look quite right to us and would be a safety hazard. Head meet mantle. Again, with my smaller house I KNOW someone would hit their head.

I envisioned the wall(s) with only tile capped by the mantles and painted drywall above. Simple. Not liking any of these common treatments above, my idea was to end the mantles a few inches short of the edge, which would mean a few inches of tile on both ends of the mantle wouldn't have anything to die into except drywall. My woodworker, who made the island counter and will finish the mantles, also installs tile so I thought it best to have one person handling both installations to avoid miscommunication and facilitate easier installation. Though he doesn't agree with this possible design choice, he can slightly round off the top edges of the tile to ease the transition to drywall.
I can't really find photos of this online to illustrate my idea. Probably because its a bad design choice. But I'm stuck. Would my idea to do shorter mantles with tile that dies into nothing but drywall look wackadoodle? Any alternative suggestions to avoid head banging, but still get mantles, tile, and drywall?

3. TILE LAYOUT. Assuming the tile is acceptable, I move onto layout now in order to purchase the tile online. We'd like to use the 12x24" tiles laid horizontally. I've got no experience at this so let me know how this looks. The mantles need to be at least 7" from the fireplace. I do not like how this leaves a small strip of tiles at the floor. I do, however, like the looks of the upper section. I had two shorten the top row of tiles so the mantles wouldn't land too high on the wall.

I thank you in advance for trudging through all this with me. I'd like to have this done before Christmas to **finally** be able to properly hang our stockings.