Geoff, you have duplicated your posts here. Suggest you close one down or it can get very confusing. Sorry I don't know the first thing about wallpaper.

I think the first layout is fine. You might want to consider moving the door for the storage room of the master bedroom so that it opens into the hall. That way the kids can use it for overflow storage. Also, that hallway is big enough that I think it could hold a large armour, providing more closet space. (There's no need to sleep in the same room as your clothes, so long as they're not too far off.) Also, don't forget that while the drawing shows kids in double beds, this need not be the case, so there will be more room for furniture (dressers or whatever) in their rooms. Finally, that step to bedroom 4 will not be odd at all. I've seen it in other homes. It looks clumsy in the drawing but it isn't. What you'll see when you come up the stairs is a bedroom door on a slight diagonal. It's only an odd jagged step if you walk like a robot, in straight lines along the wall, which is what your eye is doing on the drawing but you won't do in real life.

Have you thought about getting slipcovers made? If you wanted to go with a cottage look white or off white would look good with your rustic fireplace. Don't be afraid of the white, slipcovers that are made well will last a long time, and can be washed even bleached. I have had mine for probably 9 years now. Love that you can wash them. I would skirt the bottom of the slipcovers. I think it would really transform them. You could bring in some blue accents with pillows, etc. Some pictures on your wall with some ocean blues would look nice with some rustic touches like antlers, shells etc.

Thanks :) Yeah decided to go with tile. So sand cement is ok over existing tiles if I prep them first? Only problem is, the new pad can only be about 30mm at it's thickest (leaving up to 15mm for tiles) otherwise it'll end up being higher than the hallway floor. So I either need to make the fall shallower or not bother with the waste and make it all level. If I made it level, could I use levelling compound at that thickness or would deck mud/sand cement be the best option? Also, should I be putting in mesh for strength? (I know I should (and will) ask the local hardware what they suggest, but it's great to have suggestions from the Houzz community also)