I don't know either of those towns (and it appears Eichtersheim is a subunit of Angelbachtal), but I am familiar with Kraichgau, the general name for that region of Baden-Württemberg. It lies in the area east of the upper Rhine valley, between the Odenwald and Schwarzwald mountain ranges. To be honest, it isn't the most fascinating corner of Germany, but if might prove interesting if you can find family roots. More on that later...
1) Getting to these two villages doesn't appear particularly difficult via public transportation from Heidelberg. You just take a regional train to Wiesloch, then hop on a bus. The trip lasts anywhere from just under to just over an hour, not a whole lot longer than it would take by car.
If you decide to go the rental car option, it isn't that difficult either. Traffic on A5 and A6 (the two Autobahn routes you would take) can be tight, but nothing unmanageable. Heidelberg has a couple of speed traps that you should be aware of, however. If you choose to drive, send me a PM and I'll tell you where to watch out.
2) The Neckar River Valley upstream from Heidelberg is one of the under-publicized gems of Germany. Similar to the more famous Mittelrheintal, it features scenics towns and castles lining a mountainous gorge as the river winds through. The highlights are the castle town of Dilsberg, Hirschhorn, Neckarsteinach, Eberbach, and Bad Wimpfen. Especially Bad Wimpfen. You don't need a car here, as there's a good regional rail services that runs along the river.
I love the Odenwald mountain region that surrounds Heidelberg. Another under-rated gem. I spent three years hiking through here every chance I had, but for a quick visit, I would recommend the towns of Lindefels, Michelstadt and Erbach. Getting around here without a car, though, is very difficult.
B5, as it runs north of Heidelberg alond the western foot of the Odenwald is named the "Bergstraße" (mountain road). It follows an ancient Roman trading route and many of the towns along this route specialize in wine. A series of castles also overlook the route, including Burg Frankenstein, from which Mary Shelley named her famous scientist. The towns worth visiting on a short visit include Weinheim, Heppenheim and Bensheim. Just off the road, the small town of Lorsch contains an abbey that dates back to the Carolingian period, plus one of the cutest little town sqaures you'll see anywhere.
3) Just some general advice. The region you plan to research bore the brunt of several French invasions throughout the centuries, was almost completely depopulated as a result of the Thirty Years War, and also took a beating late in WWII. Consequently, much personal history has been lost. Not trying to discourage you, but don't be surprised if you visit and find that the civil records only exend back to the late 1940s.
Older German records were hand written in a now obsolete script called Kurrenschrift. Even many native German speakers today have difficulty deciphering it. So, you may want to call ahead to a local church or municipal office to see if anyone is available who can help you. You may not even be able to recognize your family name without assistance.
