You have a great area there. I'd think about the amount of space you're going to dedicate for laundry storage and working surface for folding or drying clothes. If you have an interest in hanging clothes to dry, there are some very clever hardware fixtures that drop down from the wall or hang on the ceiling Pantry storage Chances are that you'll be able to free some space once the water heater tank is gone. I'd think about the amount and type of storage you would like for a pantry storage and shelving - do you have daily food, utensils, kitchen appliances, long-term food storage from discount stores? What size cabinets or shelving will fit in the room? 6' 3" width minus the depth of your washer and dryer and a decent walking space leaves how much room for a cabinet? Is there enough room for base cabinets with shelves above in the area beyond the washer and dryer? The other thought I have is to consider buying or building shelves that have adjustible-height clips or "pilasters" (industry term) that allow shelves to be moved up and down. Pilasters are metal tracks that have mounting holes that would allow you to mount shelves or drawers, picture below. Google "shelf pilaster" to see a pic.

If you mean configuring the laundry and powder room into the utility room space, then a remodeling contractor should be able to help you with placement/code or maybe other ideas. I think, in an ideal world, we could all have all the space we need for all the elements in a house we want. But I'd rather have a powder/laundry combo, if I've determined that I need another 1/2 bath, rather than make do with one less bath than my family needs because some people object to having a W/D in proximity to a toilet, or whatever it is they object to. If you can squeeze enough space, I like the kinds of doors that pull out and tuck into the sides of the WD to hide it if you feel the need. I had both of these pics saved when I was trying to figure out how to move my w/d from a too small for today's large W/D units laundry room to my main floor bath. The first one is a bit hard to see but the doors slide/tuck in beside the machines.

In general I've seen outlets mounted lower to the wall and water drain and shutoff higher. You want everything to be accessible though especially if there is a problem and you have to unplug or shut off the water quickly.

So sorry to be negative too. The pantry there will be a small walk in. Creating a bigger walk in will be a matter of taking space from elsewhere. So what are you willing to give up to have more walking space? Unfortunately , I am not a fan of a walk in pantry, unless it is more of a scullery kitchen or has cabinets and counters where small appliances can be or an extra ref/ freezer, etc. It looks like there is a door that goes into the mechanical room which really throws off that area. This was a rough idea but you would have to do pocket doors Is this house built? Does it have that angled wall? I would consider stackable w/d and see if you can move that outside door towards the dining room. It would allow you to take some space from the hallway and use it in the laundry/pantry. There's some really talented folks on here! Can't wait to see what their thoughts are Good luck!