You change your game mode to survival or adventure
Press T and type /fly in mutiplayer. Note that this will only work if you are a mod and there is a flying mod installed. In single player, double press space to fly. Press shift to descend and space to go higher.
You can only turn off the rain if cheats are enabled. If they are, the command is /toggledownfall
Turn it off. Sorry :(
pull the battery out :P
The button "O".
First off you must be updated to the latest version of Minecraft Xbox Edition, then you go to your world and under Gamemode change it to creative, then you can double tap A to fly.
Buy a Mac
/gamemode a
/gamerule mobGriefing false
turn off the firewall is all you can do.
You press E or Escape on the keyboard.
You can't turn off the timer since it's a demo game.