I found this Australian standard for you - though i do wonder if it should go up a bit with people getting taller and taller every year! "Australian Standard 3590.2-1990 states fixed height keyboard desks should be in the height range of 680 mm to 710mm" You could also test out your dining table to see if your desk chair fits under it at the right height.

Do you have any other access to the backyard? Lane at the rear etc? If not... I like your plans but I wonder if you will miss the access down the driveway. Possibly a problem should you sell later on, or should you need to bring large amounts of materials etc into the rear yard. I'd think about using the front of the house for all the bedrooms. Possibly the sun starved middle room for the master suite. Extending it though to the room you have marked as pantry. I can't see the dimensions, so I hope it's big enough. And use all the rear space, minus the bump out, as living. You could maybe pull the kitchen into the centre, looking out to the yard, pantry + laundry behind it against the for mentioned bedroom. Splitting the living area up a little. And giving you much more living space.

I have been planing my new butler's pantry for a while and here are some of my favourites. My space is 2.8m x 1.5m (L-shaped). I am having 450mm wide bench with open shelving top and bottom on the long side (maybe one row of open drawers like in first photo), 650mm wide bench at the end with sink and cupboard below. I also have a small alcove on the left which will be used as a broom closet (easy access for spills). In your case I would run the bench and overhead cupboards from the window, along the right hand wall and back around to the door. You could then have a study desk under the window with the natural light. You may also have room to put a fold down ironing board cupboard all alternatively put in a pull out ironing board in the bench that returns near the door. Good luck!

I agree with above, go with shelving that spans the full width (but not necessarily full height if you don't need that much storage - anything you put up will probably affect the usefulness of the ceiling light you have in the nook). Plain white shelves like this would go fine with the other shelf you have