Definitely agree that tall windows and doors are an asset, and a fantastic selling point for later on if you decide to rent or sell. They keep with the feeling of space, which feels luxurious. The only thing is, with our Australian summer and all, keeping light out, depending on the direction the windows/doors face, may be of concern. Incase you were considering this point early on, too, just wanted to let you know there are block out long drop (240mm) roller blinds available. Best of luck with your decision - can't wait to see the end result!

You could lower the ceiling but don't forget insulation to deaden the noise, and maybe a manhole at the junction. Alternatively you could use cloth or something to make a tent like ceiling and use foam around the piping. https://www.homestratosphere.com/make-exposed-pipes-chic/

my suggestion would be to keep the new kitchen in proportion to the size and scale of the whole house so i prefer option 2 with cabinets only as high as the top of the window, tall narrow fridge (less than 80cm wide) next to the back door with wall mounted mw and wall cabinets all round, no tall cabinets, more counter on the fridge wall then stove, sink and dw along the window wall to make sure that there is counter on either side of the stove and sink and locations for a toaster, kettle and other appliances..but exact location of appliances depends on budget and sizes of all the cabinets you want to use.. but, if you plan to remove gas in future, why not start with electric appliances and best insulation ready to add solar power at a future date? ...eg check out the electric air sourced hot water heaters and consider an electric flame heater for the kitchen fireplace and save the gas heater for the hew rear living area although it may be possible to have one heater with hot air connected to the other rooms with an in roof ducting system and, if you have long term plans to alter the rear lean-to research options for renovating the whole house and then plan all the work in stages...eg i would have the new laundry/bathroom next to the refurbished bedroom (master suite?) and have the future new rear living area with the north aspect

after tiling to the ceiling in my high ceiling old bathroom i've decided that "next time" i would prefer to keep the tiles in line with the top of the architraves around doors and windows...tiles are there for a long time and so many tiles make me feel like i'm in a public bathroom and although i love the look of the new bathroom i miss the opportunity for some colour and/or texture with paint or wallpaper that can be changed so much more easily, cheaply and more often that extra high tiled walls