Re: stereo volume.
Your stereo is looking for a line-out; the Fuze is of course a headphone jack. There’s an impedance mismatch between those two. It makes for crappy sound. You can turn up the stereo and make the crappy sound louder, but I’m guessing that’s not what you’re looking for. Unfortunately there’s no good option.
The Sansa Base Station (and others) are very good options. They use the 30-pin connector, not the headphone jack & plug into your stereo system via the AUX IN jacks, so once it’s hooked up your stereo sees it as a compatible input device like a casette, CD player or turntable.
You’re right in that counting on the Sansa alone to power home stereo system speakers through the headphone jack is ridiculous. There’s just no way! But the available docking stations “bridge the gap” and charge the little bugger to boot!