Dynamo

I think they meant literally

She seems to be sleeping but we don’t know if she’s sleeping well

I think both would be great. Make public transit better AND introduce a general speed limit. We don’t need to choose only one option.

I‘m all in favor of a general 130 km/h limit on German autobahn. In addition to being better for the environment, it would make our already relatively save autobahn even saver. But I have a feeling that the speed limit in Germany is similar to the gun discussion in the US. It’s a very emotional topic for many people.

To signal intent to overtake flashing the light (outside of settlements) is legal and described in the StVo. It’s not illegal. Doing so while driving very close to the front car while they have no chance to make space can be „Nötigung“, yes. The situation described by OP falls under the legal use of high beams in my opinion.

Polite or not, in German driving school you are taught to use either the horn or flash your high beams to signal intent to overtake. So flashing the high beams from a distance could be seen as polite since you will not ride their ass before they have time to move to the right to let faster traffic pass.