alright. I know a little about RPG's, so I'll address each question individually.

1. Dice in RPG's are generally used to determine success or failure. When you attempt to do something that is not relatively easy, like score a hit with a weapon, you would make a roll to determine your success or failure. Trust me, sometimes the failures are more fun.

2. Generally, the storylines are planned out by the person running the game, called a GM, or Game Master. However he or she does their storyline is up to their own personal preference. Generally, the players only have to worry about the backstories of their characters, especially with the FATE system

3. Again, this is a generalization, but the characters are usually in some sort of a group, which can be for any number of reason. It can be as cliche as you happen to all be in a tavern or as complex as a tale of friendship over many years. Their interpersonal relationships, however, can be almost anything. As you role-play your character, try not to think what you think of this person, try and think of what your character does.

The characters should easily interact with the story if the GM tailors it to the goals of the character. I play a mercenary-like character in Dungeons and Dragons, so a quest to rid some dormant  evil from the world wouldn't be interesting to me unless said evil has a large pile of treasure or other goodies or the fellow characters offer me something. (which they generally do. Let's see the paladin open a lock)

4. We are waiting for a role-playing game designed and developed by Evil Hat Productions. The game system will be a new version of the Fantastic Adventures in Tabletop Entertainment (or FATE) system which is based upon the fudge system.