"I want to update the tiles with tile decals. " In front of a fireplace? Looks like you use this fireplace, and you expect decals to last exactly how long?

Hi there - I am going to say few things that will make me sound like the bad guy, but don't kill the messenger. It appears you have a standard wood-burning fireplace in a manufactured home that has had unvented gas logs added. Assuming my powers of observation are correct, there are a few things you should know. The stone wall panel is probably only held on with about four screws. If you look very carefully between the joints in the stone, you will probably find where the screws are. You can probably just unscrew the screws and take the whole thing off. You'll have a blank slate! If nothing else, you can take the panel out to the garage or yard to experiment with colors without worrying about making a smell or a mess indoors. If you wanting to paint it, I'd start with a block primer, which will help to deal with the porosity of the stone. Otherwise, it will probably be three coats of regular latex primer. A good semi-gloss latex paint is the best thing to use around a fireplace. It handles the heat better than solvent-based finishes. Don't paint the hearth, no matter how much you are tempted. If you don't like the color, replace it with another non-combustible material. Also, FYI, if you look in the installation manual for that fireplace, it was not approved for the installation of unvented gas logs (those kinda look like Temco Amercan Dream logs to me, but I could be wrong). Technically, you can keep the logs, but the damper must be clamped open, which means they won't heat the same way anymore. Running the logs without the damper open could create a hazardous situation. The heat deflector hood should not be covering the upper louvers. It will prevent air from circulating around the fireplace, which creates a potential hazard. You will not need the hood if the damper is open. Don't run the gas logs with the glass doors closed, in case anyone forgot to tell you. Hope that little bit is helpful. Happy re-decorating!

There is a RustOLeum muted gray spray paint intended for BBQ grills. You might consider painting it with that or a similar product designed to withstand high heat. https://www.walmart.com/ip/Rust-Oleum-Specialty-High-Heat-Ultra-Silver-Spray-Paint-12-oz/196486786?wmlspartner=wlpa&selectedSellerId=2419&adid=22222222227066487799&wl0=&wl1=g&wl2=c&wl3=192936394920&wl4=pla-306315930177&wl5=9011064&wl6=&wl7=&wl8=&wl9=pla&wl10=113134491&wl11=online&wl12=196486786&veh=sem&gclid=EAIaIQobChMI0pqIu6ve5AIVRR6tBh0Oyw_0EAQYBiABEgLbwPD_BwE No fireplace "needs" a mantel if you don't want one; however, if/when you remove it, do expect to find some brackets that were holding it that will need to be removed if you remove the support board, too. You might be able to remove the mantel shelf and its supports and leave the board that is flat against the chimney and, perhaps, cover it with a new fireplace surround or build the surround beneath it and paint that board either the same color as the chimney or the same color as the surround.

Since it appears that the original fireplace is a woodburner with gas logs installed, you need to keep a non-combustible hearth extension, You can cover up all of the exposed sheet metal on the fireplace, which will give you more of a low-slung, linear look like you show in your "after paint" photo, but anything that covers the face of the fireplace must be non-combustible. If that 's drywall I see on there, it needs to come off. Unless you have a specific purpose for shelves on that wall, get rid of them in your design. Let form follow function. The size, height and arrangement should be connected strongly to your purpose. Stone always looks better al the way up to the ceiling. I would only go somewhat wider than the fireplace to create a strong focal point. Unless you have a mid-centruy modern aesthetic you're working with, placing stone on the whole wall will make the texture less special, Since your fireplace is already raised off of the floor, I recommend against placing the TV over it, not because of the height of the TV, but because it will be an awkward fit. Come up with a side-by-side arrangement you both can live with.