NKBA recommends a minimum of 42" counter to counter for a one cook kitchen and 48" for a 2 cook kitchen. You can probably get away with only 36" between island counter and side wall to the right of the range. Less than that and you'll have a pinch point in your kitchen.They recommend a minimum of 44" behind a seating counter to allow people to walk behind seated diners. I spec'd my aisle between sink/DW and island to be 45". That's wide enough to allow me to have both the DW door and island drawers open to unload straight from DW to island drawers. Definitely upgrade to drawer bases. It's worth the cost for the increase in storage capacity. We removed 69" of upper cabs during the remodel but because we went from base cabs, most with roll out trays, to all drawer bases, we have room to spare. I'd make that decision again in a heart beat.

I think you can combat your worry about "washed out" with wall paint colours and accessories. I like the Taj Mahal and I also like the Silestone. I assume you are aware of the upkeep and maintenance issues that marble brings - although it really is gorgeous. Look for posts from Beth H who is amazing at offering really lovely choices for tile. Tilebar is a great place for choice and they have a good sample policy so order a few in and see what you think, but choose that after you've finalized your counters and they are installed. With either the Silestone or the Taj Mahal, you may be looking for a light grey tile for your backsplash. Of course, there are other colours you could choose from too and maybe a more colourful choice than grey will help you get over the worry of the room being washed out. I'm finding that my own preference is longer tiles, not just the regular 3 X 6 subway size but something a bit more elongated. My all time favourite though is herringbone. I know the choices are overwhelming, but do some browsing in Houzz pictures and see what really jumps out at you. Think about what makes you happy, rather than worrying about making the "right choice" or worrying about resale etc.

@Beth we ended up sticking with the t pulls due to pricing (i found a bulk pack and it was much cheaper than any other options we looked it). Unfortunately, we had to sacrifice some things we would have wanted due to budget. I tried my best to update the house while still acknowledging that it is a 100 year old home, which is why I kept the wood floors and chose the door style that I did (we also had to keep the doors on top with exposed hinges due to the original style of the doors and the cabinets themselves, as we could not afford new ones). Originally, this house had wallpaper everywhere that had been painted multiple times and white vinyl plank, which was a nightmare to keep clean). We went right back down to the original floorboards and tried to find a balance between old and new/modern while still keeping to our budget. All things considering, I think it turned out alright for a couple of amateurs on a budget haha!

While we wait...... I have bright white cabinets with Silestone Calacatta Gold. I think Simply White might clash. We took a door sample to stone yard. There are lots of discussions about pairing different whites. Some I like, some not so much.