B1 German for Permanent Residence (Niederlassungserlaubnis)

Not necessarily. EU Blue Card holders can get the settlement permit after 27 months with A1 German, or after 21 months with B1 German (§18c Abs. 2 AufenthG). The shorter period requires the higher language level.

No. B1 is the standard. EU Blue Card holders can use A1 after 27 months, and recognised refugees need A2 after five years. The requirement is waived if you cannot meet it because of a physical, mental or psychological illness or disability, and the authority can waive it to avoid hardship.

Yes, if you completed it successfully. That means a DTZ result of B1 and a passed "Leben in Deutschland" test. It then proves both your German and your civic knowledge (§9 Abs. 2 AufenthG). A course finished with an A2 result is not a successful completion.

Yes. §9 AufenthG also requires basic knowledge of the legal and social order. The normal proof is the "Leben in Deutschland" test, which is part of the integration course.

The Berlin and Munich authorities accept a degree from a German-language university programme as language proof. This is authority practice, so confirm it with your Ausländerbehörde.

Yes, in three cases under §9 Abs. 2 AufenthG: if you cannot meet it because of a physical, mental or psychological illness or disability; to avoid hardship, at the authority's discretion; or if you can speak simple German and were not entitled or obliged to take an integration course. There is no general age limit. Berlin asks for a specialist medical certificate.

B1 (intermediate) means you can understand main points of clear standard speech, produce connected text, and describe experiences and plans. A2 (elementary) covers only basic phrases and routine tasks. B1 is significantly more demanding.

The Berlin and Munich lists ask for a valid passport, proof of income, health insurance, your pension insurance record and your language proof. Neither asks you for a certificate of good conduct. Requirements vary by Ausländerbehörde.

There is no nationwide figure. Munich, for example, states a processing time of up to 12 months. Ask your Ausländerbehörde and apply as early as you can.