If you post the exact train journeys you are taking and the days you are taking them, we can give better advice.
The big advantage of the rail pass is flexibility; except for ICE Sprinter, you can hop on any train. This convenience comes at a cost; these days, if you know which trains you are taking and can commit to non-refundable and non-exchangeable tickets, you can save a fortune. To give a real example from 2012, when my mother and I went from Berlin to Dresden and back: the full fare was €38 per person each way. The advance purchase fare each way was €19 for one person, and €29 for two traveling together (which we were). So, by using the advance purchase tickets, we saved €94 on that one round trip! We also made seat reservations (€4 at the time, now €4.50), which were a very good idea. The trains were crowded, and on the return trip people were sitting in the aisle on their luggage, but we just went to our reserved seats, stowed our bags, and relaxed.
You can buy the advance tickets on the Bahn (German Rail) website http://reiseauskunft.bahn.de/bin/query.exe/en, following Rick's tutorial: http://www.ricksteves.com/travel-tips/transportation/trains/online-schedules. You print the ticket at home; it will say you need A4 paper, but 8.5 x 11 works fine. You can print as many copies as you want (one for each suitcase, money belt, etc), which covers your concern about loss (I'm a worrier about that too, so I always have LOTS of copies). To use the ticket, you need the credit card you bought it with; the conductor scans the barcode on the ticket, swipes your card, and you're set.
It really is easy, and unless you're taking a lot of rides or need total flexibility, it's the way to go.