Cable positions 2 & 3 likewise and connect all of them to the 'load' of the cooker switch, ie the cooker switch will isolate all 3 appliances.
Thanks, I think this is the most helpful advice from all.
personally I wouldn't recommend these as it would be too easy to turn the 'cooker' off for cleaning and forget about the fridge
You're right and I haven't thought about this before. I will choose option C.
at full load leaves 1.6KW for the socket
From your calculations, it looks like you're considering 245V. I thought the base voltage was 230V in the UK, but 245/246V is what I actually see in my meter tests.
I mean, it varies during load, of course, but it was interesting to see you saying that, makes total sense to me. Looks like I should use 245V as a baseline.