2004-10-04
Any abilities which have already resolved before the coin flip are not undone. Any abilities that trigger when it attacks which have not already resolved will still resolve.
2004-10-04
If the Djinn attacks, but you lose the coin toss, then it is still considered to have attacked, and any other abilities that trigger on it attacking will resolve normally.
2004-10-04
The coin flip is done as a triggered ability on declaring the Djinn as an attacker.