For sure I understand running a three conductor cable on a long run I have one going out to my garage even and then there is a sub panel. When the OP was saying his breaker number 6/8 the light should have come on as I’m hoping 6/8 is a 220 breaker and when you shut one off you get both. It would be very dangerous to test half of an outlet thinking power is off and then only having half the outlet dead. I just finished wiring my kitchen and I don’t see needing to do something like this. I have 3 circuits for receptacles and in each case the first one is a GFI and then the second is connected as a load.
In the OP case he is doing it backwards it seems splitting the 220 at a non GFI and then running to a GFI.
He also shows in his last drawing that he is continuing the 220 run to each of the remote GFI outlets. I didn’t know of any that you can split that’s why I asked if that was something special (220 GFI split outlet) if not he needs to take the black wire away from the one run and the red the other and supply the GFI with just 110.
Just thinking out loud here but if I was going to take this approach I think I would make the first box of each run a two gang junction box with a partition barrier. Something like this: http://www.smarthome.com/25402/Two-Gang-Deep-Wall-Box-34-6-Cubic-Inches/p.aspx
I would use two GFI outlets in the one box and then run my load outlets off of this keeping everything GFI.
You could then divide the two 110’s inside the box and keep it all separate for someone coming along in the future.
I don’t know if that is to code or better than the OP’s setup that I gather is to code also. I’m sure the pros will sound in on what code says.
If you were wiring this today for 4 cercuits with 4 outlets, it would look the same but you would run a 3wire between the boxes, the red would connect to the black going to the second black.
If he followed my instructions in post 18 the red takes power to the second box and the black was capped off in the first and second box.
So what you were recommending is every box get a GFI outlet and the only advantage of the 3 conductor circuit is to pass thru the other leg of the 110 saving wire on the runs between the panel and the kitchen. None of the outlets will then be split. 18 will power A 20,E 26,C 28,D and 6,B the red wire coming from 8 to circuit B needs a nut. Assuming 6/8 is also a 220 breaker. None of the outlets will be wired as loads.