Remember, I write for the non-German (Americans, English, French, etc). So this is an essay of advice on how to make use of German mass transit.
If you get hired for some German company and start the planning process....somewhere in the mess....you will come around to transit opportunities and discuss the idea of going car-less. So, I'm offering these observations and ideas.
Every area in Germany is broken down into a 'zone', and ticket costs are relative to that zone. As long as you live and work within that zone, then you've hit the lowest possible price for transit costs. An example would be Wiesbaden-Mainz....which lies in the 6500 zone. The city of Wiesbaden with all of it's burbs on one side of the river, and the city of Mainz with it's burbs....are all within the same zone. You pay for one single zone and enjoy the transit opportunities of the entire region. S-bahn, regional trains within the zone, buses, and trolley-car.....all fit within the same package of transit.
If you stepped into a second zone....say adjacent to Mainz? Well, you'd pay for two zones in the ticket price, thus boosting the cost of the whole deal. It'd likely add thirty-percent onto the cost. Going into a third possible zone? You'd boost the ticket price by fifty to sixty percent.
All of this would lead to think.....you need to identify the place of work (the zone) and limit your search pattern for a house or apartment to that one zone.
All major urban areas (Berlin, Koln, Frankfurt, Munich, etc) operate within the same logical way of zones.
Then you come to the day-pass, the week-pass, the month-pass, the year-pass, and this after-9-AM pass.
Cost comparison will lead you to discover that a year pass is the best economical deal. You will realize that it's a hefty amount they want for a twelve-month period. Most operate with a deal of deducting X amount from your bank account for 10 months, and thus pay off the entire year ticket. The other tickets (from day to month) are usually decent prices. The after-9-AM ticket? It's a unique ticket that says you won't travel prior to 9-AM in the morning. It usually can only be bought for a week or a month, and it means exactly what it says.....you can't get onboard the train or bus until after nine. Cost savings? Figure roughly thirty percent.
Could a guy make it with just mass transit, a bike, and occasional use of Uber or rental cars? Yes. But only in an highly urbanized German city. I wouldn't put Trier or Kaiserslautern on that list.
Bottom line? If you get offered a German job and make the move.....do your research to the ninth degree.