Solutions for overheating? Thermal paste replacement?

CPU idles at 45-55 degrees celsius (on a hard surface)
50-60 degrees if I used while charging or while in my lap
75-90 degrees when playing mildly demanding games or running more demanding programs

I know the CPU shuts down at 105+ so the CPU is not at risk. I’m curious how the high temperatures affect the surrounding hardware in the case if the 80+ degree temperatures are sustained for several hours, daily. I’m thinking of replacing the thermal paste on the heatsink. What kind of difference in temperatures can I expect if I do this?

Mid-2012 Macbook Pro 13″
Intel Core i5 2.5 GHz CPU
Mac OS High Sierra
Solid state drive