A 38 inch walkway would be too tight for me and does not meet kitchen design minimum recommended clearances. Forty-two inches is the minimum recommended for a one-person kitchen. With counter overhang you will end up with 35 inches of walk space. Put a bookshelf or high table 35 inches from a wall to get a sense of space and move through it. Will a dishwasher open into that proposed 35 inch walk area?

I have 48” aisles in a much smaller kitchen than yours and I love the freedom of movement even when several other people are “helping” in my kitchen.

Hood height and venting must meet the recommendation of the hood manufacturer. This varies per hood. I hate having the sense that a hood is in my face due to 30 plus years of a hood microwave, so several well-loved hood manufacturers on this forum were immediately off my list. I placed my hood based on the height of the tallest person in the family (5’ 10”). .I could have gone two inches higher, and it would have still looked okay for the kind of hood I bought.

You will have to meet code for your municipality....you should be able to find that online. I was surprised by the things that were required.

I don’t think that 38” aisle is a code, but I wouldn’t want to go less. NKBA recommends 48 for a multiple cook kitchen. We have 42” counter to counter (45” cabinet to cabinet) and that works well for us, with multiple cooks. 45” would be even better. I certainly wouldn’t want to go less than 38” counter to counter, even for a one cook kitchen.

Your vent hood installation instructions should tell you how high it should be mounted.

I don’t know the rules on electricity but there are certainly some and they are not general, they are very specific. Our kitchen has a LOT of outlets, because that was what was required by code. It is every so many feet and we had to have 2 on the island because it was 9’ long and they couldn’t be under an overhang of more than 6”, although we did sneak a 3rd “convenience outlet” under the overhang by a stool. Ours all had to be a specific power and are all either GFCI or tied to a GFCI receptacle. If you are doubting the info your GC or electrician are giving you I suggest calling your inspector. I found they were very helpful when I had questions through the planning process and even granted me a couple of exceptions for some smaller things.

You need 42" minimum from counter to counter NOT cabinet face to cabinet face. I have a 38" kitchen aisle and just this week I was thinking I don't care how much it costs we're going to have to move a major wall 10" someday to get a decent aisle width.

Don't do less than 42!

2 20 amp GFI protected small appliance circuits are required. More is better. No point on your counter can be further than 24” from an outlet. Any piece of Counter 12” or larger requires an outlet. Any peninsula or island requires an outlet. More is better.

Code also encompasses manufacturer’s requirements. So, if you refrigerator is among the many that requires a dedicated circuit, that’s required by code as well. It’s a best practice, even if it’s not required. Same with your MW. Your DW and disposal share a dedicated circuit. As does your hood. Some gas ranges want a dedicated non GFI circuits, because GFI can mess with some of them. Some fridges too.

So, 4 circuits minimum for a kitchen, but with more appliances, like an instant hot, or ice maker, etc. you could need 10 or more.

Very often pre 70’s homes do not have a large enough panel to do a modern kitchen remodel without doing a panel upgrade. Some need a service upgrade from the pole to the panel.

You have to read and understand the specs for everything.