Three things -

I would at a minimum trade the ref and the oven. This is because I use the ref a lot more than the oven, it makes an easier route to the ref from the sink or cooktop, and I have a chance to get into and out of the ref while people are seated.

Which is the another thing. You may not be able to open the ref door while people are seated, or at least without the thrill of potentially hitting someone. I know this is shocking, but a 36" wide ref has at least a 35" wide door which means it will stick out into the aisle at least 35" plus a little bit more here or there for handles and door depth.

A seated person sticks out into the aisle about 24". You have only a 42" aisle from the counter edge to the ref (without handles). The seated person and the ref door overlap by about 18". Excepting its likely worse than that. The island really isn't going to be 36" wide, it will be about 39 to 40" wide. A normal cabinet is around 24" deep without its doors or a decorative back. Both of those elements add 3/4" each. The countertop overhangs the front of the door by another 3/4". So the counter top is 26.5" plus 12" for a seating overhang or 38.5". Because your other aisle is already narrow (will actually be more like 38" wide, the seating aisle in front of the ref will be about 40" wide.

Personally, I would get rid of the island seating and use a 30" wide top. I would want an aisle of about 60" (but at least 54") where seating is in front of important appliances.

The last thing is I know you think its safe to have your cooktop with a seat in front because you placed a 42" tall counter behind it. It's not to me. Poor dh actually lit a newspaper on fire seated at that exact position. There is something about the raised bar that "feels" reassuring even when its dangerous. Aside from fire, spatters and splatters of hot fluid will easily go high and further than you think. Over time, I grew to resent the height of the stools and the loss of workspace right beside the cooking surface.

I strongly encourage you to build a full height wall, but only right behind the cooktop and to consider having the seating at the counter height instead. I would tell you it was cheaper, and it is because the hoods are so much cheaper, but honestly, it will occur to you that you can use the difference on really fancy tile.

Thank you very much for your feedback, much appreciated. I will definitely take out the seating at the island, clearly there isn't space there. That was a recent addition to my plan and not well thought out.

Regarding swapping the fridge and oven, I'm concerned about how close the edge of the fridge would come to the edge of the counter top on the sink wall. It looks like less than three feet to me. My fridge is 32 1/2" deep so 36" with handles. Also, if someone was standing at the fridge with the door open it would prevent anyone from passing through the kitchen to/from the family room. This is a major artery in my house so I'm reluctant to block it. My thinking by putting the fridge in the corner is that the traffic could walk around the other side of the island if needed. What do you think about that traffic flow issue?

We have gone back and forth about the raised versus counter height for the back of the cooktop. Since it is such a long peninsula I'm wondering where you think the plugs might go? We were thinking the raised bar would provide a perfect spot for those receptacles. Also, do you think it makes sense for me to consider an induction cooktop from a safety standpoint? We are willing to extend the counter top so the seating is even farther from the cooktop.

I completely agree that it would be preferable to have the cooktop facing a wall. I started out this project with that intention, we just can't find a layout that we are happy with that has the cooktop on a wall.

I know - that's why I'm saying make the wall behind the cooktop only about 3 feet wide. Sabjimata did something similar, just with a bigger cooking surface.

I didn't see that your ref was that deep. I'd likely still waste the pen and ink or more of that roll of blue tape and see how close it could be and still feel ok. Or if I could just clip a foot off the island and get a better path. You will know if you've reached obsession when you build a cardboard full-size model in the garage :)

Part of that is because I use the ref way more than I would have thought before I asked dh to write down where I went while I was making meals. If someone had asked me, I would have said I did mise en place but it turned out that I'm more mise all over the place. To help with my style, I ended up doing sink, range, prep surface, ref, corner pantry - all tight in a line.

Not suggesting that for you - don't know how you cook! Just not sure that you'll be long term happy having to run around the island for a cuppa milk. If you have an accomplice, you might try writing or filming the cooking process for a meal or two. One of the crazier things you can do is assign a value in steps to each bit and see if doing the same thing in the proposed plan takes more or less walking.

Here is a link that might be useful: sabjimata's kitchen