What is the legal definition of renting a room out vs renting space in a house? IF the rent is split evenly does that mean the sub renter can put all of his things in the house next to things with the other renter? Does renting out a room mean that if the house has two occupants that both parties split the utilities?
You can customize your lease agreement for nearly anything. If you want to be the go between on who can place their milk on which side of the refrigerator ... that's up to you (as long as you don't violate Fair Housing Laws) you have that latitude.
What I'm suggestion is that legal definitions aren't useful in this situation. Crafting an arrangement that positions your rentals to generate the most VALUE - which should help you generate the most NOI is the name of the game.
So, if managing the utilities is something you want on your plate, then write an all-inclusive lease.
If you don't wish to be bothered, then make Tenants jointly responsible for utilities, etc.
Best to you.