How do the positions of the equinoxes and solstices with respect to the horizon depend on the latitude?
An equinox occurs when the plane of Earth's equator passes the center of the Sun. On the two equinoxes (around March 20 and September 22) the Sun rises exactly in the east, travels through the sky for 12 hours and sets exactly in the west. Every place on earth (barring the poles, which are special cases), irrespective of its latitude, experiences a 12 hours day and 12 hours night on those two days. So, latitude positions have no effect on the position of equinoxes.
The inclination of the Earth's rotation axis causes position of sunrise and sunset to change every day. The maximum angular distance between two sunrises or two sunsets is the angle between two solstices. This angle changes with the latitude of the place. It is minimum at the equator, and after that increases according to the latitude until it causes the midnight Sun in the polar area. The further you are away from the equator, the more extreme (farther away from E and W) the positions of the solstices. Thus, sitting at 24^o North, if you get 14 hours of daylight in the summer solstice and 10 hours of daylight in the winter solstice, sitting at 52^o North, you would get 16 hours of daylight in the summer solstice and 8 hours of daylight in the winter solstice.