I only use wifi at my house and when I go out I leave the wifi mode on (ask to join networks off), does this mean it's constantly searching?
If you go into your WiFi settings you can turn off "Ask to join Networks" so while you're out your WiFi won't constantly be trying to connect while you're using data. This way it will only connect to your home WiFi.
Yes, it'll do that. It doesn't take that much battery because the system will wake up, search, find nothing, and switch off on its own.Yes it's true that it won't connect to wifi or ask you to connect. But your phone doesn't know if you'r at home or not. So it will power up the wifi antenna and search for a familiar signal (your home wifi) each time you take it off sleep.
I only use wifi at my house and when I go out I leave the wifi mode on (ask to join networks off), does this mean it's constantly searching?
Turning the phone on uses battery, so yes, using anything on it will also use battery.
Yes, it'll do that. It doesn't take that much battery because the system will wake up, search, find nothing, and switch off on its own.