Steemit:
- The flag is indeed the down vote button.
- Steem is blockchain based and mostly uncensorable. However Steemit decides which blockchain entries it displays. Things that get down voted disappear from Steemit but remain in the blockchain. It's up to users to police themselves by down voting inappropriate content. There are no moderators.
- Yes
- Steem is the blockchain database. Steemit is just one user interface to the database. Steemd.com is another. There will be more in the future.
- Dunno
Steem:
- One must have Steem in order to be able to post or curate content. So, Steem is an access token first and foremost. And, the more Steem (or Steem Power) you have, the more influential you are on the platform--that is, the more your vote counts and the more exposure your posts will get. Since everyone wants influence and exposure, Steem has value.
- Please read the whitepaper for details. Steem Power is essentially just locked or restricted Steem. Steem Dollars are tokens that always have a value near 1 USD.
RE: A few questions about steemit