If your camera dont do binning for lower resolutions and so become more light sensitive, then you should use the highest possible resolution and bitrate
You should not conserve memory card space, and surely not if you have a large enough memory card.
Wear and tear on the memory card are just the name of the game, and one day it will be worn out and you need to replace it.
I am on the cusp of starting recommending 128 Gb memory cards instead of 64GB for each camera in a system.