Yes, the functions of the dock needed for the Slot Machine applciation are provided b the iPhone or iPod touch. The external charger is only needed to charge your device while it is docked.

While the dock is powered via the 30 pin connector of your device, it uses ultra-low power circuitry which consumes no significant power from your battery. In fact, it could be powered by a potato battery because it requires so little power. As one example compared to the normal functions of your device, it uses less than one thousandth the power of the just the display backlight.

Definitely, all you have to do is turn your music on, go to the settings button located on the bottom of the Jackpot Slots home screen, and turn the background sound effects down or off. If the background sound effects aren't bugging you, it can be left on and your music will automatically play over the background sound effects. Your music can be listened to using the iPhone speakers or your headphones.

All you have to do is unplug the Jackpot Slots device and plug it back in again. After that it should be working fine.