#1 Smallest wheel is usually almost always most energy efficient. (same tire outer diameter is kept)
#2 steel wheels fit over bigger brakes. So sometimes you can fit 1" smaller steel wheel vs aluminum wheels. Steels wheels are also more aeroydynamic as there is not poles to twist the air. --> you need to use wheelcovers to get best aero. many stock ones are good enough.
#3 Wheel or tire weigth impact to consumption is going to be minimal. In a city you migth get 1% better FE but you cannot measure it. So buying expensive ligthweigth wheels is usually waste of money. If you get them cheap go for it if they are also aerodynamic. or can be made aerodynamic. Best option is ofcourse ligth and aerodynamic wheel.
#4 bigger tire diameter lower RR and lower wheelwell drag but increases drag (ground clearance. These usually is similar impact so in most cases no gains to either direction. Migth give little good in selected wisely the rubber compound that has low rolling resistance.
#5 tire rolling resistance is very important specially on heavy vehicles.
#6 narrow tires lower drag, but I recommend installing them to wider wheels. It boost performance on all areas.
My video series on the matter on youtube: