Any question answered...

Increased charging current -> increased heating in battery -> generally viewed as a bad thing unless using a peak detection charger (unlikely with a laptop)

http://en.wikipedia.org/wiki/Boeing_787_Dreamliner_battery_problems suggests yes, your laptop may blow up, house catch fire etc.

But if he's just buying a laptop power supply, one with the same voltage but more current will be fine. All the sophisticated charging circuitry will be built into the laptop and/or the battery pack.