Details won’t be finalized until May 20, but if approved you may want to skip the rental car this summer!
https://www.bahn.com/en/offers/regional/9-euro-ticket-en
Yes. But just a note, this is only valid on Nahverkehr, so the local trains, but not the fast ICE/EC trains.
So if one wants to go long distances, it will be very slow travel with very many changes of trains and likely quite crowded cars.
And at least within the first two weeks (I expect things to normalize after that), it can develop into a frustrating experience, when the trains are overcrowded and you can't get a seat. Or if you have one, but the train doesn't leave because of overcrowding, and the police will clear it.