Yes, that's correct. Honnan is a question about a place, "from where" (together with hol - "where" and hova - "to where"). Merről is a question about a direction, "from which direction" (together with merre - "in which direction").
So sehonnan, mindenhonnan and valahonnan mean "from nowhere", "from everywhere" and "from somewhere", respectively. Semerről, mindenfelől (using the postposition felől instead of the pronoun merről), and valamerről most directly translate to "from no direction", "from every direction", and "from some direction", respectively.
------- perhaps greek mythology has influenced how english-speakers think about wind and winds: They were the children of Aeolus, the Keeper of the Winds, and Eos, the Titan goddess of the dawn. The four gods were Boreas (North Wind), Notus (South Wind), Zephyrus (West Wind) and Eurus (East Wind).
Big 6 nov 18