Absolutely no problem changing up the carpet. Things to watch for......make the transition in a doorway, an opening or along a visual break in the rooms (like the corners of the walls). I would stay in the same colour range, but just go to the other end of the spectrum rather than change the colour completely.....like light grey going to dark grey, not light grey going to navy blue. You want the separation but an easy transition on the eyes.

Home stagers sound great!

Provided there is 1200mm clear between the breakfast bar and the opposite bench then by rights, you should have ample room and if that's the case, I think I would opt for the design with the kitchen on the eastern side. My reason; you get a much greater feeling of open plan by having the dining and lounge on the North/South plane. I like the large WIP in this one - on paper at least. The second plan somehow feels wrong. I personally don't like the idea of having the breakfast bar being located in the lounge. If it were me though, I would ask for a 3D CAD plan of both kitchens [to walk through on the computer] before making up my mind on which one to opt for as it gives you a much clearer vision of what the finished kitchen will be like rather than looking at a flat plan.

windows in master bedroom need to allow views and privacy and much as i would prefer bed on NE this keeps the bed in view towards and from family room so prefer bed on south wests wall and small sliding doors pushed towards north side of room with tall narrow window beside sliding door and highlight window for light with privacy and wall space for chest of drawers...acknowledging theta the pwdr doesn't have a window but my suggested arrangement uses less total space more efficiently and is better for older kids and long stay visiting parents (more people can use the various options at the same time) and a small ventilating skylight will exhaust and brighten the toilet and vanity area ...the wide door into the lounge can be a stacker or stable door so you need to investigate local options (and everything is expensive unless it does what you want...we always use solid core doors that can be ten times the price of a basic hollow core door but love them so we economise elsewhere) and barn door between entry and family would be OK as long as you like them and it doesn't compromise lounge doors but could look ok if both doors are the same style and different widths...and location of dishwasher is personal and if you have already been unhappy with sink in main kitchen then have it in the scullery...main advantage of my suggested kitchen location is that it's closer to the front and the family area and external doors and the pantry uses the central space that can be much better illuminated with another ventilating skylight instead of a tiny external window and noisy exhaust fan