thank you for contacting our community.
1. You can call the Ausländerbehörde or write them and email to ask for the form.
2. I cannot tell you for sure. As far as I know Ausländerbehörde normally doesn't approve while Dublin is still running, but as all Dublin-Deportations are stopped at the moment because of Corona, it's worth trying.
3. The money you received before according to "Asylbewerberleistungsgesetz" will be cut depending on how much you earn. If you live together with your wife and the money you earn is enough to provide for both of you, her money will also be limited or cut to zero.
I hope my answers were useful for you and I'll be very pleased if you contact me again with further questions. I'm a member of the MBEON-staff and I‘ll be glad to guide you over a longer period of time. Mbeon is an online consultancy for migrants via the mbeon-app, which you can install on your smartphone for free. Download it via App Store or Google Play Store. You'll find me In the mbeon-app under my name „Euskirchen, Frau Schaefer“ and get confidential one-to-one advice in a safe virtual room where nobody can wiretap messages. Further information: www.mbeon.de