It depends on how you define your God(s). If you're a pantheist, polytheist, animist, etc. divinity is viewed as immanent in the Cosmos, the Cosmos itself is seen as divine in its own right. So you would see the actions of divinity all around you.
- "I guess Thor has been busy in Asgard. That would explain why nobody's seen him here on Earth."
Thunder and lightning are his manifestations (or manifestations of his actions), so you see him in action every time there's a storm.
"Thor also played a large role in the promotion of agriculture and fertility (something which has already been suggested by his blessing of the lands in which the first Icelanders settled). This was another extension of his role as a sky god, and one particularly associated with the rain that enables crops to grow. As the eleventh-century German historian Adam of Bremen notes, “Thor, they say, presides over the air, which governs the thunder and lightning, the winds and rains, fair weather and crops.”[7] His seldom-mentioned wife, Sif, is noted for her golden hair above all else, which is surely a symbol for fields of grain. Their marriage is therefore an instance of what historians of religion call a “hierogamy” (divine marriage), which, particularly among
Indo-European peoples, generally takes place between a sky god and an earth goddess. The fruitfulness of the land and the concomitant prosperity of the people is a result of the sexual union of sky and earth."
http://norse-mythology.org/gods-and-creatures/the-aesir-gods-and-goddesses/thor/
- "Nun's realm is the cosmos. It wouldn't make sense for him to come to Earth."
Nun didn't tend to be viewed as a personal being:
"In ancient Egyptian mythology and religion, Nun was both a place or a state of being and a god who animated that place or state of being.
Nun was the name the ancient Egyptians gave to the primordial waters of chaos that were all that existed prior to the creation of the cosmos. In most of the various
ancient Egyptian accounts of how the cosmos came into being, Nun was “merely” a passive source of raw materials that the creator god – usually
Ra,
Atum,
Amun, or
Ptah – used to fashion the world.[1]
...
The conception of Nun as a passive location or state of being was more widespread than the conception of Nun as an active force; in an important sense, the latter was only an extension of the former. All bodies of water, including the Nile, were referred to as “Nun” at some point. Stillborn babies and those who failed the
Judgment of the Dead were banished to this realm, and thus to effective nonexistence by being formless – having utterly lost any trace of their earlier identity and being “nothing” in the sense of being “no-particular-thing.” And yet, since all form and existence ultimately sprang from Nun, it was a place of infinite creative potential. The underworld was often equated with Nun as the formlessness through which even the righteous dead who passed the Judgment had to travel before being reborn, the same route that the sun god followed during the night.[5]"
http://egyptianmythology.org/gods-and-goddesses/nun/
- "God X was killed/banished/whatever by god Y. Of course we wouldn't expect to see God X wreaking miracles."
The deities of indigenous religions don't tend to care about "miracles". They're more concerned with overseeing the laws of reality, not breaking them for the sake of magic tricks. "Miracles" are basically an Abrahamic concept.