Great overview. Finally we all can understand how this works
But one thing I am not so sure about:
Furthermore, if you, after the first strike of a doublestrike, move any enchantments away with ET and then back to the same creature with another ET, then it may receive the bonuses again on the second attack.
This does not sound very realistic to me. A creature can only benefit from Cards like Bear Strength once per attack action. F.e. you can reveal the card for the first strike of an double strike attack or wait for the second strike. But receiving the bonus and then moving the card two times does not allow you to use the bonus once again in the same attack action.