We have traveled by rail in Italy, Germany, Austria etc. on a Pass. This was in 2016 so things may have changed. As far as the cost decision between the Pass and individual tickets you can probably do the math fairly easily. Paying for the seat reservations was worth it for us as seniors.
If you are willing to pay for it we found First class to a good choice. The seats are better, there is more space for bags and ( at the risk of being non-PC) the atmosphere was more enjoyable.
Another note of advice: sometimes the connection times can be rather tight and there can a long walk between platforms in the larger stations.
I also can’t tell you which might be better, a pass or individual tickets.
I will echo bedell’s suggestions. It may cost a small amount more, but business class tickets were worth the extra couple of dollars. Having a place for luggage was a big issue.
A friend and I traveled around Germany in 2009 on a Eurail pass. It was good for four days of unlimited travel. The conductor signs off on each day that you travel but no one signed on one day so we had a free day of travel. You buy it in Canada or the States and it must be validated at any station ticket office. For five trips, I would do it rather than individual tickets. You will need to pay a supplement for a seat reservation but that’s not much. Also first class travel can be reasonable- I needed a train from Berlin to Amsterdam. The train I wanted was full in second class. A first class ticket was only 5 Euros more than a second class ticket. it was worth it.
I would say Nein to a Eurail or Getman Ral Pass. For such short journeys, just use the DB Navigator app. Some of thise journeys might be on RE trains, some on IC or ICE. First class on the latter is very nice. In summer and definitely on weekends, trains are crowded because of special passes.