Gate charge and switching speed — what 18 nC Qg means for the driver
Total gate charge is 18 nC at 10 V gate drive. For a 100 kHz switching frequency, the average gate-drive current is about 1.8 mA — well within the output capability of a standard gate-driver IC. The 1900 pF input capacitance at 15 V drain bias tells you the driver sees a moderate capacitive load; a 1 A gate-driver will switch the MOSFET in tens of nanoseconds, though the miller plateau will dominate the actual switching loss.
Junction temperature range — -55 to 175 °C
That 175 °C ceiling is the absolute maximum junction temperature — the 47 W power dissipation rating at case temperature assumes you can keep the case cool enough to stay below that limit. In practice, for an under-hood automotive or industrial motor-drive environment where ambient hits 105 °C, the 8 mOhm Rds(on) keeps the die temperature rise manageable at moderate loads.