You can make a custom map on minecraft with out a map editor by building or demolishing certain land features or you can use a seed by typing your seed in the bottom box on the "create new world" menu.
no
Try using a map editor, like MCEdit.
if your device is jailbroken, get myfile from insanelyi repo, go to the app, lets say minecraft pe, go to documents, games, com.mojang, minecraft worlds, select ur world, scroll down 2 "open with..." select hex editor, ther you go.
Invedit. An Inventory editor.
Currently, no. A good search 'round the Minecraft Forums might yield something, but as far as I know, MineEdit is the only entity editor, but it's oudated.
You can always use an inventory editor. I use INVedit
You download the template on the minecraft profile page, open it with paint (or some other kind of photo editor), and you edit it from there.
Try MCedit. See the link below.
No it can not. Stop being so paranoid :P
You use any kind of editor, like MC edit, and you just load
Yes there is such thing as the Ether World in Minecraft.