SOA for bipolar transistors is a slightly different issue as it is limited by secondary breakdown in the high voltage/ high current corner.
Mosfets don't have this problem, and after generally limited by thermal conditions in the corresponding region.
When switching, the mosfet briefly goes through a linear region where the peak dissipation is typically half the power consumed by the load. The temperature rise depends on both how long the mosfet stays in this state, and how often it is in this state. The faster you can switch the mosfet, the lower the energy transferred to the mosfet and thus the lower the temperature rises. This can be really important if you have a device rated at (say) 2.5W switching a load of maybe 50W many times per second.
Because the gate has a capacitance, the amount of current required to change the voltage on it is inversely related to time taken to do it. High current (and especially low Rds(on)) mosfets have a higher gate charge, and thus a higher gate current is required to switch them. Gate drivers which can supply 4A of gate current are not unusual.
Knowing the gate charge, the Vgs(th), the load voltage/current, the switching speed, and the thermal characteristics of the device, you can quite easily determine if you need just a pull up resistor, a fancy gate driver, or something inbetween.