danielonn,
1. Unknown. My guess is they become Admiral Club with no PP access.
2. Unknown but it seems like it.
3. oneworld
4. If you mean after the merge, then there will be no "operated by." Everything will be AA.
5. AA
6. It will be AAdvantage, so I assume you'll lose the DM number. However, with CO/UA it went the other way. The new program was MP but you kept the OP number. It seems like they did that because they retained CO's technology. AA seems to have better IT than US, so mostly likely everything DM will go away (online booking tools are more advanced and for example you can book some partner awards and one-way awards online)
7. So far it seems like it.