Questions about Work Visa (Anmeldung, processing time, etc.)

Hi everyone!

I have accepted and signed a job offer with think-cell, a tech company in Berlin. I will relocate there in one month. I have yet to get my Anmeldung or start my work visa application.

1. I am going to live with my boyfriend in Leipzig (1.5 hours away) and commute to my office in Berlin for work (my employer permits remote work, so I will only need to be in Berlin 2-3 times per week). When applying for the work visa, is it acceptable for my Anmeldung to be registered in Leipzig even though my employer is in Berlin? Is it possible for the immigration office to deny my work visa because of this difference in cities? Would it help my chances to provide documentation or justification of why/how this commute is going to work?

2. Can I apply for my work visa at the Leipzig immigration office instead of the Berlin one (because it is less crowded) even if my employer is in Berlin?

3. Do you recommend any additional documentation to accelerate my process or increase the chance of approval?

4. Is there any way for me to start work before this work visa is approved?

5. With an secure employment contract, am I pretty much guaranteed approval of my work visa?

Thank you for all of your help!
Amanda