I would suggest your plumber links the hot and cold fill pipes to the supply UNDER the sink - this gets rid of unsightly pipes and while he's there get him to move the taps to the L side of sink. I would then create a broad drop down counter top to create a place to sort your laundry ready for hanging out to dry or to fold ready for ironing This drop down counter top to be hinged to R side of washing machine and ensuring the taps are not impeded. If you can't do the drop down version then create a free standing top made out of a piece of MDF/laminated board to put over the sink and washing machine for clothes sorting & folding. This free standing top can 'live' at the side of the washing machine when not needed. I would then put shelves above the folded back counter top to store washing powder and sundries. I would store the washing powder etc in colourful or white boxes to keep the place looking tidy and uniform. Handles on the boxes for ease of access. Oh I do love organising - can I pop round and do this for you? Hope all goes well with the changes.

Here are a couple moore ideas. I like that the brightly colored collection adds to the decor in the first one. The second one is great if you have room to hang them in on the rod. Simple shower curtain rings would do the trick.

You say the kids come in the small door and then bring their stuff to the large door to drop it? I think the "mudroom" needs to be at the small door. Anyone who brings their stuff out of that area has to clean the glass doors next time they need it. As for the guest entry, you need to get something bigger than that desk, and your picture needs to be lowered so the center point of it is 5' above the floor (you'll have to calculate the centimeters.) Consider making the investment to reverse the swing of the door so you can make the best of the larger wall to greet your guests with a console or credenza and some decor.

The options....