Mimir well is near where all creation began in a place of information, knowledge and wisdom. Creation began at the roots and started to grow and expand. Like a tree grown from a seed buried underground. Not a real tree but growing and expanding like one.

Great narration; But you lost me when you said: "It is unknown.." I'm going to need sources. We know from the Voluspa in the poetic Edda that The AEsir and Vanir were at war and made peace, and the prose Edda states that Mimir was one of the hostages given in exchange between The Vanir and the AEsir, when they made peace. This is a pretty clear indicator that He is of the AEsir, especially considering how early the war happened. Sources on it being "unknown"?