Is only used for powdery like, or liquid such as blood, dust, oil, etc. Mamire is meant for physical items. However, this physicality can be stretched enough to include things that are related to a physical state such as failure or trends which both of which show the current state of something. Similar to mamire, [darake] is similar and can be used for both physical and abstract concepts.
それを言うならば、埃まみれ hokori mamire I'd rather covered with pride than dust, though.
In 4175 「血に」の「に」が必要ですか
This is similar to darake, but mimare is only for liquids or powders like blood or dust, whereas darake can be for these things and things like mistakes, and holes (as in a car riddled with bullet holes).
inevittable, I'm pretty sure 4175 needs the に because まみれ is in its verb form and not followed by だ or だった。
tmkain is absolutely correct; if it was まみれ as in all other examples you could say 血まみれ。「彼の顔が血まみれだった。」「彼の顔が血にまみれた。」