Hi Jacaroo Bunny, I would start by choosing a new floor tile or vinyl plank (possibly less expensive) and then select a wall paint colour that coordinates with your cupboard paint, floor tile and bench top laminate. If they're all completely neutral it might be worth considering a splash of colour on the walls, such as a pale, warm yellow or cool blue. I personally really like Porter's Paints Limoncello (yellow) and Attic (blue). To give the room more of a refresh perhaps you could consider painting the doors, architraves, skirts and ceiling in varying lustres of the same paint colour you used for the cupboards. I'd also remove the window treatments and replace with simple roller blinds - but only if you need them - for sun protection or privacy. Replace the wall shelf with a floating IKEA Lack shelf in white (again, colour permitting), and add a cute wicker laundry hamper in the corner. It's tough to offer advice re: room unseen, budget and design aesthetic unknown, but best of luck anyway. :)

If the rumpus is going to be used as a family day care room, then I think the powder room should be accessible from there. This will make it so much easier for one person to supervise the kids in the room as well as the one who is heading off to the toilet. Perhaps you also need a wet area in there for cleaing up after messy activities. I know someone with a similar family day care set up, and they have toilet and laundry attached to the back of the garage/daycare space. And then the kitchen is adjacent, this makes life a lot easier for the sole person in charge of the kids.

Look at the range of timber bench tops at Bunnings. Nothing better than a timber look, with real timber. https://www.bunnings.com.au/our-range/kitchen/benchtops/timber

Question only you can answer. Why did you want the big laundry in the first place? Would a euro laundry be sufficient for your household.? For occasional guests would the specific guest bedroom be an unused space for great lengths of time. A laundry is used every day. I suppose you can store the brooms,vacuum, ironing board, in the guest suite.....