@Jacob Mallat
As far as a second kitchen in the basement, it is best to find a space below the kitchen upstairs simply because that is where you'll have a drain line you can tap into for the sink downstairs. Regarding putting a washer/dryer upstairs, same thing, find a space where you can tap into a drain line. Whether that is a bathroom closet behind your shower, or somewhere in the kitchen are going to be the best spots and most affordable. Have a plumber come by and see what spots would be best.
I am not sure how you are going to be the renting the space, STR, MTR, LTR, rent by the room, but I would just include all utilities to make it easier. No reason to go through all the trouble and money to have a submeter. Regarding the kitchen downstairs, having a second oven (in my municipality) is against building code. Be sure to look into your municipality laws. We rent our basement unit out with a door in between our upstairs and our basement unit landing technically not making it an ADU or a duplex. That is unless your single family home is zoned for a duplex.
Let me know if you have any other questions, good luck!