Walking around Positano

Criminal safety would not be an issue I would concern myself with, but I would investigate the road to make sure it is lit and there is a shoulder, etc. Google maps should help, or ask the host--but it is probably going to be steep (I personally like this after a huge Italian meal but not everyone would). Sometimes in Italian villages you will have a pathway or stairs, but sometimes you are stuck walking along a road with cars zipping by.

Daylight will also be short in late Sept, and it wouldn't be any fun in the rain. I'd have a solid plan B in place for getting around should conditions not be optimal - or safe, visibility-wise - for making this walk, especially if there isn't a dedicated pedestrian path.

Positano is not very big but I'd choose something closer to center.

You might check with your lodging to see if this bus stops near your location.

http://www.positanoeasy.it/sito/sites/default/files/timetablemobilityamalficoast03_06_2016.jpg

It's a different bus than the Sita bus for the Amalfi Coast towns. It also runs later.

sk,

Keeping in mind that Positano has a lot of hills, I'm not sure I'd want to be walking uphill for 1.2 miles. That's also going to be a bit of a hike to get to the boat dock for the trip to Capri. As far as the "safety" aspect, I doubt that criminality would be an issue but traffic safety could be.

I'd also suggest looking for something a bit closer. Are you committed to staying in an Air BnB, or would a nice hotel suffice?

I think thT would be very inconvenient. It will take longer than you think with all the hills. And traffic is an issue.