Guilds and Raids - Q&A

Hi.

I have some essential questions as well:

1. Do we have to beat all other tiers before we can enter the last heroic tier every day?
2. Can you do multiple raids (of the same tier) a day?
3. Is the reward for the raid based on the contribution (aka most damage dealt = best reward etc.?) or does every body get equal reward no matter the contribution?
4. You were speaking of limited attempts for toons and dead toons can only be used the next day again: Does this mean limited attempts for every player individually or will there be something like a guild-limit of attempts?
5. How are we getting notified that a raid was started by the guild?
6. Can there be multiple raids of different tiers at the same time?

Thanks in advance