Love your style and you've got some beautiful furniture there! A deep aubergine purple velvet on your wingbacks would look stunning. I'd tend to stick to purples in this area to keep it classy. Also, a dark purple would be more practical with kids than a cream. I'd keep the chairs you've got, unless they are really wobbly. Get someone to check them out and give you a quote for repairs and then you'll have a price to work against to see if you can get cheaper. OnePlan is right on the style and yet I don't think they look out of place in the room. I also like the idea of bench seats or if you wanted something really different, you could get a church pew?! I don't think the room has too much dark furniture as it is a large light area. Keep us posted with pics/samples of possible fabrics you find. Also, check out fabric outlet places.

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.

I would get a better chandalier with better lighting and IMO DRs do not have to be bright as they are mostly used in the evening.

Everyone has some valid points and so I would also recommend moving the clock to the kitchen wall and place the wall unit under the mirror. Centre with the table with the additions of some artwork each side if the clock with wooden frames to match the clock. Find a low piece of glass or pottery or a runner to tie in the grey shades. I presume u have a grey lounge suite. Change the lighting as to what was suggested by People Space ARchitects.