Does temperature always increase or decrease at the same rate? if not what might influence the warming or cooling rate

No

Explanation:

Rate of temperature increase and decrease changes with the height from the mean sea level. When looking at the geotherm a gradient the increase of temperature with respect to depth is 25-30 degrees. The temperature increase with every 100m of depth and similarly the temperature decrease with the lapse rate of 6.5 degrees per kilometer, with every increase in height. At the height of 35 km, the temperature increases with height at the rate of 5 degrees per kilometer, then again at the mesosphere about 80 kilometers in altitude the temperature usually decreases as the height and can be as  -95 degrees.

Cpopulation density

None   they are   equally likely to occur on any plate boundary