there is no perfect dimensions for an island. Try to organce space subdividing into smaller cabinets of 60x60 cms which is the max space for a structural division and works for seating area as well

Sophie, Patricia you are right cleaning the crystals would be a hell of a job. Hence I would like to look at designs like the other pic I attached which is I believe from the e.ion range of Falmec. As I have mentioned before this is a second chimney. The primary chimney hood is above my gas job in the kitchen countertop and is the main and daily area for cooking. This is the secondary area which I plan to use for some quick heating, occasional stir fry etc. The pendant chimneys that I have come across in brands like Elica and Falmec do not require ducting. The filter needs to be changed every 6 months or more. With my kind of usage I am assuming I would need to change it even later. What I am looking for is different brands which have pendant chimneys. Right now I am only aware of Elica and Falmec. I know Siemens and Bosch don't have it. Siemens has 2 models which are like a flat rectangular panel to be attached to the ceiling or false ceiling. But the cost is same as the Falmec chimney. My only respite may be the cylindrical Isola chimney models from Faber or even Hafele which are ip within budget.

The island works in the plan provided, you might even make the island longer. 42" clearance will work between island and cabinets (36" if not much trafic, and no appliance door swings).

Totally doable as long as the island is not too bulky. And of course if the circulation space around the island is at least 3'-0" wide. You don't need too much space to move around in a kitchen because you should be able to pick up a hot dish and put it down on another surface without having to move too much. 12'x14' is a large size and a work island would possibly make the space more practical to use. In the pictures attached, the work island is only 2' wide but 4' feet long