You must make a server to do that. Making a server is free, but requires a lot of steps. I recamend using Modcraft to make your server. It does everything for you. I am not sure if making a server is safe. The only "hacks" i hear people do is speed hacks and flying hacks. But you might want to be sure that it is safe.
On the main screen there is a link near the bottom of the page, click on it and go to a "world" by clicking on it. My recommendation would be Opticraft day server.
just direct connect
Play it in survival mode or creative mode. Don't press the multiplayer mode.
It has survival mode which is rather fun and multiplayer as well. : D
Minecraft Classic and Survival mode (singleplayer and multiplayer can be played on the browser but it may be faster if you download it. [You have to pay for Minecraft survival but you don't have to for classic]) I'll post more games when I find them, but Minecraft is the best game in the world in my opinion.
SMP stands for Survival MultiPlayer
To fly in survival mode you need to craft the eye of ender
Yes.
Survival and creative single and multiplayer
yes and is a great game to paly
There is nothing obligatory about minecraft; there is nothing you should get.
Yes.
NOPE
#$# $#$ #$# # = Gunpowder $ = Sand