1. "Turbo charging" won't damage the phone. The battery is 3000mAh, so any charge under 3 Amps is safe. (The cutoff for lithium batteries is 1C - 1 time the capacity of the battery.) And the battery will last just as long if you charge it at a 0.1A rate or a 2.99A rate. (The life depends on how deeply you discharge the battery - if you never let it get below 40%, you'll get tired of the phone long before it needs a new battery [besides, the battery itself is only about $15.])
2. If you use a stock charger (the kind you find in a dollar store or pharmacy), it has 5 Volts output, so it won't trigger the turbo charge, and it'll charge at a slower rate. A turbo charger, feeding the phone 9 Volts, kicks it into turbo charge mode.