I can't make a list of absolutely everything, because that would take hours. But you can check out the minecraft wiki (link under "Sources and related links" below this answer) for all the crafting recipes.
in 1.4 with an anvil to repair them that is or cheaper way is to put for example 2 swords in the crafting table and it will repair them
You can't get a curved shape on minecraft. Everything is squared.
check out minecraft wiki it has everything you will ever want to know about crafting sequences.
no you can't. I've tried EVERYTHING! I just don't think you can.
everything
Its kind of hard to say but click on this link to the minecraft wiki. It will tell you everything you need: http://www.minecraftwiki.net/wiki/Tutorials/Setting_up_a_server
You will have to rebuild them.
In my opinion minecrft is fun. You can play with friends, make your own server, make huge kingdoms, and everything you could dream of in blocks.
I didn't make Minecraft.
Download it off the minecraft forums. Then drag everything in the file into the minecraft jar on winrar, or 7zip.
You can download different Texture packs to make everything, (ground, blocks, buildings, etc,) look anywhere from cartoonish to real life.
There are no keys in minecraft!
Infinite, as everything in minecraft. However, they are quite rare, and it is easier just to trade for them.