Just like your namesake, a gas-oven is inefficient, fuel thirsty and not good for it's environment
It is a necessity of combustion that you draw in air, therefore you must constantly vent hot flue-gases into the kitchen in order to cook. IMHO, the "sealed box" environment of an electric oven is better-suited to the task.
Hobs are a different animal,-I believe induction is very energy-efficient, followed by Halogen( but you can buy a HUGE amount of electricity with the price-difference! )........ceramic and Radiant are low down, as they produce heat from the underside which the designer attempts to reflect up to the utensil.
IMHO, the flexibility and instant response of a gas hob, outweighs the loss of heat through flame-spread and convection.
leccy oven, gas hob, best gombination
old enough for wisdom, young enough to be compos mentis.