You can if the kitchen joinery is a dark enough black, the walnut is stunning. Presuming your timber floor is if any would also be mid toned, the black joinery would simply be a personal accent, and would work best if it's included in small furnishing details elsewhere. I think this would be the same as people with timber floorboards wanting to have black or iron furnishings, including sofas and coffee tables, that wouldn't be dismissed at all, so I think this has merit. I would however keep colour to a minimum to avoid a confused cohesiveness. There's quite a lot of black and beige being done in modern design, because it's organic and can striking and warm at the same time. It's quite architectural and high end. Go for it. I would love a black walnut kitchen!

Just to throw another option into the mix – look up Marmoleum for your kitchen floor – it's a modern version of linoleum (not vinyl!). It comes in the most amazing range of colours and looks (about 300 to choose from – from very bright primary colours through all the secondary and tertiary colours, marbled or stripey or plain), has all the green credentials (97% natural components like linseed oil, wood flour, jute etc; nearly 50% recyclable content and 100% biodegradable – it even smells great when it is first laid), extremely hard-wearing, easy to clean and maintain, comes in either sheets, tiles or planks and it is quiet to walk on. It is used in hospitals and schools because of it hygienic characteristics and doesn't give off volatile gases like vinyls. We have put it down in our new kitchen about six months ago and I love it. One of the things I love most is how quiet it is – no clicking, clanking noises as people walk on it. It sweeps clean easily, wipes clean (for spots), mops beautifully every now and then and looks wonderful. Highly recommend it!

mischiefdebs has good suggestions. I would clean it up but without losing the natural, rugged look. Change the base and platforms. Don't waste it on cats 'though, put potted plants on the platforms. Definitely don't put it in the garden unless you want it to rot away in no time. Don't despair, it has great potential. ;-)

I like all the garden ideas ( it does look a bit sparse and 'rental property' look about it IMO ) , with a low fence along the front , a wooden screen a couple of metres in front of the door , etc , BUT when I looked at the very first photo -- the wider angle one -- the one thing you notice first is the yellow marker post on the left hand side of the driveway fence . So take that as a cue , and paint the garage door a bright colour to stand out -- primary or metallic or trendy , just one that you like , and personally I'd probably change the curtains ( or even dye them ) to the same colour as the garage door . Right now , everything is various derivatives of off-white and red brown earth brick -- needs a decent spot of colour to lift the houses look IMO . Another option would be 'natural' timber blinds , especially if you had them the same shade of stain as the screen and the front fence , but I'd still do the garage door ( and maybe the guttering ) your current favourite colour .