I know to never GFCI a fridge provided the outlet is behind the fridge
so it cant be used for anything else.

Honestly I think you should get a pros opinion before you begin as to
the capacity of your main panel to handle the new sub panel.

sadly copper price has skyrocketed today because of this it might be
cheaper to buy a gas stove at a second hand shop and gas dryer too.

the electric dryers cost to operate is going to kill you, same for
electric hot water tanks, low capacity and high operating expense