For purposes of rendering efficiency, should all the little details like phone poles, fire hydrants, fences, cars, tree foliage, and grass foliage be set to static, stationary, or movable meshes?
Also, what lightmap resolution should I use for my landscape that is default size?
Any other efficiency protips I should know?
any object that has animation will be movable meshes by default, whatever you import, ue4 will set the correct default setting.
You only want to change a static mesh from static to movable when there visual glitch on it and has no time or workaround to fix it.
Lightmap resolution should be around 128 or 256, going beyond mean there something wrong with your lightmap uv channel (unless you doing some cinematics sequence). Higher resolution will cost more vram.
For landscape you should test different resolution as am not well experience with landscape.
Whether your meshes look good with lightmap depend on how well it lightmap uv is made in blender.