Protect your wall tiles with cardboard and take a hammer to the row of counter top tiles that are against the wall. Break them up good. Wearing gloves and using putty knives and screwdrives pull out all the little pieces of tile from that row closest to the wall. Wiggle them out from under the backsplash tile, they should come out fairly easily. This clears a distance the thickness of the tile for the counter to pivot up upon removal before it contacts and loads your backsplash tiles. If that proves to not be enough set the depth right on a circular saw or rotozip and zip through the cement board and pry that off too. It will take more finesse then normally is used when demoing kitchens but with a little caution, it should be very doable.

arcy_gw- I have thought of replacing the entire backsplash but I haven't come up with anything I really like better that also works with cabinets. I'm open to ideas though (just not subway tile- not my thing!). The island and hood are painted black and slightly distressed. I do like the contrast too so I have no plans on changing that. The words on the hood are things like "family, gather" it's ok but they will probably get painted over eventually though. Olychick- You may be right. I do love the copper but now I'm wondering if I should chose something lighter instead of adding more orange/red tones. I'd love to nudge space into a little update. Hmmmmm. Thinking of replacing the island lights with something more lantern-like and airy too. Basically I'd like to give it more of a rustic with feminine touches look instead of rustic/Tuscan.

I see a problem even if most of the remaining tiles were removed. What about the tiles under the shower? Not exactly easy to cut flush or cut with a decent edge(top layer chipping). The problems with merging different tiles will be visual and height. No matter what you do, the result will be odd. Or odder, depending on color/type of tile used. Matching the height of the new tile to the old is not difficult, unless the new tile is much thinner. So, when Googling, use the thickness of the old tile to start. The design is not something others can help with without seeing the rest of the room and the tiles available. This situation is not a usual one.

Gosh, that firescreen is EVERYTHING. So pretty. I understand you not liking the tiles as much. There are definitely options that could stay in keeping with the style of the screen and fireplace. Here are a few options and as others have pointed out above, if you search some Arts and Crafts style tiles you'll find plenty of inspiration. My mind immediately thought of green. If you want tile there are lots of choices but you consider something like a soapstone or granite etc. Gorgeous colours in this one - it would make a nice border and then fill in with plain coloured otherwise. I think this is so lovely. Gorgeous colour and design. This one too. So beautiful and classic. You could have a look at some hand made tiles - have a look at Cle tiles for some options that would also look nice in your space. I'd contact a local metal shop and get a recommendation for who could look at the screen. Or if there is an architectural salvage shop they will likely have contacts for that type of thing. Please do come back and post after photos so we can see the results.