I would wait for the rug, until you have the shutters up and your furniture placed..it may take on a character of its own and you'll want to compliment. My first thought though was to coordinate with your kitchen and incorporate some black, with a black/beige stripped rug, which would be fun with the wallpaper and perhaps paint your chairs black, add the shutters and you could paint the window trim black and add a large black chandelier.

Having been brought up in a Lockwood home I can appreciate your love of the wood. I notice you have a light green bench and that would blend nicely with some similar colours in the room. I would consider having your cupboard doors replaced or sprayed to compliment the bench or visa versa you can have your bench updated with a new finish to modernise it. Perhaps you could just price out the cost of a new bench and leave the rest of the kitchen as it is. The odd bit around the dishwasher looks weird and that might be able to be fixed by curving a new bench into a small breakfast bar type set up. If there is room I would also reposition the microwave to the right of the cook top and use the existing space for a display or a lovely pot plant.

I do not have any tiles in my current house but if you think about grout discolouring and looking bad.... then I think that might answer your question. My thought - the less grout the better.

Pressed metal splashbacks are so rare! This is the first photo I've seen with a splashback like this and I'm really enjoying it.