The shared stash simply means that any of your characters have access to the same stash. So if you play for a while as a Witch Doctor, upgrade the stash a few times and leave some Barbarian items in, you could start a Barbarian character and equip him or her with the same items.
Hardcore characters though have a seperate stash, you can't farm for items for a hardcore character using a regular one.
Yes, Diablo is in Diablo 3.
No. There are Diablo 3 teaser videos on the Blizzard website.
Diablo 3 needs a constant internet connection if you want to play it, so yes it does need WiFi if that is what you use to connect to the internet. Hope this helps.
Mephisto is mentioned, but does not appear 'in person' during Diablo 3.
Diablo 3 is out now, it was released on the 15th of May 2012.
No, there is no pirate class in Diablo 3. If you mean to pirate the game, you cannot do that either.
They are all good. You need to know how to use them.
No, it is not pay to play. The only cost is the one-time price to buy the game.
You just need to buy the game. There is no online fee. It is free to play. Diablo 3 is free to play. There are no monthly fees unless you decide to use the RMAH.
diablo 1 is about 100mb diablo about 800mb and diablo 2 expansion another about 800mb
It's been over 13 years since Diablo 2 was a true Hype, so this would give you a perfect reason not to worry if Diablo 3 would be your 1st Diablo game experience.
Diablo 3 was released on May 15, 2012.