I'm a little concerned by Rick Steves caution that the Global Pass is not accepted in Eastern Europe. Will this pass allow me to travel to Prague and any day trips from Prague? The Eurail Map indicates Prague is part of the 21 country boundaries of use.
You will be fine. Eastern Europe is a pretty broad term, and depending on the publication date of the info you have from Rick, subject to change. The Chzech Republic is a fairly recent addition to the rail pass, maybe even in the last year or so, go by the info from the railpass.
Check with the Eurail website to see what "bonuses" come with a Eurail pass in the CR. Regional trains in the CR are probably included, but U-Bahn, streetcars, and buses in Prague are probably not.