I can see you like minimal furniture and clean lines so I will remember this when I comment. You are getting a new bigger tv, which I think would help balance the wall/tv ratio which is great, would you consider a long, low entertainment unit? Regardless that your tv is mounted. Have a look at this website; www.sydneyside.net.au Also, I do like the dark rug (recently bought a dark charcoal one myself) but it looks too small for the space. The next size would have worked better. Sizing is everything with rugs.

How about a water feature? Inspiration.

Depends a little bit on the style of your house , but my first reaction is the same as bigreader -- no , and almost certainly no , no , no , no , not 4 rooms in one house . Some of the schists look alright , the 80's style might suit an 80's or even 50's minimalist American house . There are some fairly cool 'wavy' panels that are available these days ; even some feature walls that look like timber ends sticking out of a wall ; wallpaper works in some places ; but one wall of brighter paint is the most obvious 'feature wall' . Faux Stone , or that ship-lap timber , or diagonal timber are about as exciting as yellowy beige or mission brown .

Can I throw a spanner in the works here , and suggest 1 stone , but make it dark ? A charcoal , a schist , even something 'mottled' using mainly charcoal and grey and brown tones - your joinery looks to be dark , the rest is presumably rendered in some off-white variation -- anything in a gold toned stone is already dated IMO , and that square look yellowy gold stone ( your first choice ) may as well be pink or purple -- it will stand out , for the wrong reasons !