Since the stove main purpose is to heat up the room, then why not the heater? The stove or the fireplace is a good decoration in a house. also good source of heat. But the idea of making a temperature hot is cool. so why not make heater and air conditioner? Lava pool below the granite blocks can heat you up like crazy. but the limit is that it can burn you, or any blocks that can be burn.
Also, we can make changing temp in a adventure mode. With this we can manipulate how the temp will affect in a room.
Airconditioner in a desserted biome house, and Heater in a tundra base house.
I have many electric suggestions other than this:
Why is the switch and buttons is a source of electricity? They are just there to conrol the electricity. they can block or they can let the electricity flow.
Why is the iron/copper blocks cannot be use like wire/through blocks? we know that copper is the source of our wire (in game too). why not let these block use to connect as conductors? well it is dangerous, i know, but be realistic ^_^
Password block, a one electric block that can send either 1 or 0..please note that what i suggest is not just numerical password block, well, it can be easy for numerical password block. Specially for the start. But my idea is a Block-Based password block. where you can activate it but inserting a certain block. I will post it once the idea is completely plotted. if you have any suggestion, add it.
Battery have its limits, like tools. Well if there is a world option that can toogle the limit of an electric source like batteries, that would be fun. specially in the survival and cruel game. the more the output you use, the more you battery will dry. ^_^
these are just Suggestions though. ^_^