I'm not sure about the fan wiring, but be aware that all 3 switch types are momentary (power is only applied while switch is being pressed) and you may need latching relays.
BTW, SPST = single pole, single throw. When pressed on either side, either connector #1 or #2 will make contact with #4
Being a rocker switch, it could be thought of as a SPDT (single pole, double throw).
https://learn.sparkfun.com/tutorials/switch-basics/poles-and-throws-open-and-closed