The door into ensuite currently opens in (hinged on left). Im thinking we will need to use a cavity slider door (which means shifting the bedroom light switches!) This project is growing!

We have a 900x900 shower and it's plenty big enough. Neither of your proposed layouts looks that great, to be perfectly honest, sorry! In the first layout, you could improve it quite a lot by swapping the toilet and vanity (centre the toilet under the window on the bottom right of the picture if possible), and having the shower door on the other wall (beside the door). Then, you could have a towel rail on the wall beside the door (i.e. behind the door when it's open), which would be accessible from the shower but hidden when the door was open. An 800x1200 shower might be a good size for your space. You'd have to choose a toilet that doesn't protrude too far, plus a narrow vanity. With that layout, you could have a long but narrow wall-hung vanity, with a big mirror covering the wall between the windows, which would make the room feel bigger and would give a good amount of storage. Also, you may find this helpful: http://www.houseplanshelper.com/small-bathroom-floor-plans.html?utm_content=buffer4aa20&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer

A very simple layout keeping the floor space within the kitchen, the WIP takes up a lot of space with not much gain, The broom cupboard could be moved to the Laundry/entrance, narrow. If the wall has been bumped out to the eaves on the deck side giving an extra 300 depth to the kitchen you could make the island 2700 x 1200 and all drawers. The wall of narrow pantry will hold all pantry needs and more, no deep cupboards to dig into. cheers

When we lived in Australia, we had exactly the same problem with our children's bathroom. We changed the wall between into a low pony wall, and converted the window behind the toilet into a storage cupboard for toilet paper and other bathroom supplies. We also put in a pocket door like you have and a fresh new shower curtain over the bath/shower. I've attached some photos which I hope helps.