May I use a smaller wattage resistor as mosfet's gate driver for a very short time?
Don't guess. The pulse capability of the resistor should be in the datasheet or associated technical information. For example, from the Panasonic manual: 



Note that no matter how low the duty cycle you must not exceed 15x the rated steady-state power dissipation dissipation (100 x 0.15) during the pulse, for the ERJ8G 0.25W series of parts. Personally, I would be more conservative than that.