I think Nodus
Client outdated means that the client (the software used to connect to the server) is out of date. You need to update your version of Minecraft.
An "out-dated-client" means someone needs to update their Minecraft app to the latest update.
No, you download the client from the Minecraft website. The account you register there is more important than the client data.
It means that your current session was not validated by the Minecraft servers. This usually happens when you use a cracked client. If you're not using a cracked client, restart the client.
If you have a cracked client, sure.
Update your minecraft.
Minecraft is no longer in the Alpha stage. It has been updated to Minecraft Beta. Update your Minecraft game client.
After you register a premium account, you can download the client from the Minecraft website.
Rcon allows for a client to talk with the minecraft server (think remote console)
Just download the new client at the Minecraft home page, or click the link on the main screen when Minecraft is opened
Not unless you have a minecraft client in beta.
It is your account that is made premium. You could log into your account from any PC that has the Minecraft client.