I would say it has to do less with scifi and more with history. Every town she stays at she wants to learn about the reason why people act that way and why the town folk hold to their tradition. Technology varies from town to town so I can see how scifi themes appear but they are not the driving force of Kino's journey.
For the last episode, the towns people where rejected from villages in the past until they where lost in the forest but decided it was a great place where no one would bother them again. This is probably the reason they treated travelers so badly, some sort of spite. Later, scientist figured an eruption from the mountain along side would occur in the future and the town decided what they did was wrong and would like their reputation healed. Kino happened to be there for the right amount of days to tell her story.
There was also a side story about the gunsmith who alludes to Kino's Master, which suppose to have taught Kino how to shoot.
Lastly I almost RAGED when Sakura appeared on screen because I thought Kino was going to die.