I own a Rolleiflex 6008 professional and I never had a problem with loading the backs. The ingenious film inserts can be preloaded and make changing film as fast as with a standard 35mm SLR camera. Also the film inserts effectively make a second magazine unnecessary, which saves weight and money. Owning a second magazine is only useful if you tend to change between different film types frequently. You may have used film inserts for the earlier SLX camera which jam into 6000 series backs.
Batteries can be refitted and bought new for e.g. at DHW Fototechnik in Germany.
One of my favorite camera I own.