No it can not. Stop being so paranoid :P
no
Invedit. An Inventory editor.
You can always use an inventory editor. I use INVedit
Giants were put in the game for version Alpha and have been taken out since. IF you have an inventory editor you may spawn on in.
Minecraft Inventory editors are completely free do download as they are player made. A few outside the game you can try are InvEdit and InvGrid. A mod for the game that allows you to edit your inventory in-game is called TooManyItems, which I recommend if you know how to mod your game.
The best way to do this would be to use Too Many Items In-Game Inventory Editor, on the second page, there is a row or so of snow slabs with different thicknesses.
xml is effectively plain text and you can delete passwords using any text editor or even a dedicated xml editor.
Mass post editor, then delete everything.
Try using a map editor, like MCEdit.
Put leather, iron, gold, or diamond in all spots in the crafting bench EXCEPT the top middle spot.You take any chosen material, these can be gold, iron, diamond, leather or fire [can only get fire if you use inventory editor].Fill in all the holes but the top middle and you will have a chest plate(Inventory editor is a mod so you would need to download it)
I would use a mod called Too many items too, I have a tutorial for how to install the mod. (See "Sources and related links" below) Too many items is a ingame inventory editor.
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.