I have a hob on my island and I love it as I never have my back to the kitchen, can see the dc, chat with guests etc. We have the extractor in the hob which means that cutlery drawer is offset which is a little awkward in terms of layout for cooking.
I would put the sink opposite the main prep space rather than opposite the hob. I don’t move from sink to hob as much (once to fill and once to drain) but much more when I’m prepping.
We have 1.1m gap which is a comfortable pivot space. Before I had 1.5m and there was always an irritating extra half step. But because hob and sink aren’t opposite it still works perfectly for two people.
We have sink, dishwasher, bin and plate cupboard in the same area so you tend to fill dishwasher on one side and empty it in the other.
I would always go for 60cm over two 30cm cupboards and try and have at least one wider cupboard too if you can fit it somewhere. Kitchen designers tend to be obsessed with symmetry but I’d always prioritise functionality.
I have space beside my oven but in practice unload to the island.
I spent a lot of time thinking about how I do things in the kitchen. I’m right handed and dh is left handed so that made it a bit trickier but if everyone has the same dominant hand you may find that you want your condiments on a particular side, or to unload your dishwasher from a particular side. The design process tends to focus on the visuals but how you move through the space will ultimately be more important.