No.
In sigleplayer-yes, in multiplayer-no.
In order to play minecraft on any computer, you need that computer to be connected to the internet to log in for the first time, or it will not work. If, for example, you have a computer without internet in some remote region of your house, than unfortunately you will need to temporarily unplug it and carry it to somewhere where you can access the internet. Download minecraft onto the computer you want, run the file, log in, wait for the files to download, and once you see the title screen, from that point on you don't need an internet connection to that computer to play. After moving a computer back to its normal location without internet, try to log in again (yes it won't work). After attempting, if the computer has previously logged in, a "play offline" button appears. Click it and minecraft should start up normally.
In a sense, yes, but in another sense, no. You do not need to install Minecraft to play it on a computer, you can simply run it in your internet browser on Minecraft.net. However, if you want to run Minecraft without an internet connection, or without visiting Minecraft.net, you must install Minecraft on your computer. You can install Minecraft on multiple computers under the same account, but your saved worlds will not sync between computers.
Yes, but you would only be able to play it singleplayer and I believe that you would need to be offline(without internet) Same goes for regular Minecraft Client.
You can only install items without the internet, but downloading items and updates needs the internet as well.
No.
In sigleplayer-yes, in multiplayer-no.
Yes. The seed option is tied to the game, and not the internet.
No. The messenger has to have Internet to work. How will it be able to connect to the the signals it require without Internet?
yes they do there is probable something wrong with your computer or internet connection
In order to play minecraft on any computer, you need that computer to be connected to the internet to log in for the first time, or it will not work. If, for example, you have a computer without internet in some remote region of your house, than unfortunately you will need to temporarily unplug it and carry it to somewhere where you can access the internet. Download minecraft onto the computer you want, run the file, log in, wait for the files to download, and once you see the title screen, from that point on you don't need an internet connection to that computer to play. After moving a computer back to its normal location without internet, try to log in again (yes it won't work). After attempting, if the computer has previously logged in, a "play offline" button appears. Click it and minecraft should start up normally.
In a sense, yes, but in another sense, no. You do not need to install Minecraft to play it on a computer, you can simply run it in your internet browser on Minecraft.net. However, if you want to run Minecraft without an internet connection, or without visiting Minecraft.net, you must install Minecraft on your computer. You can install Minecraft on multiple computers under the same account, but your saved worlds will not sync between computers.
Yes, but you would only be able to play it singleplayer and I believe that you would need to be offline(without internet) Same goes for regular Minecraft Client.
No I have have bad internet but minecraft works good.
yes
Yes, there is multiplayer in Minecraft.