I understand you 100%. I didn't have such situation on Crete, but I had about 3 dog adventures (one quite funny), the most "dangerous" on Sifnos. On Sifnos we just went slowly to the nearest fence, crossed it and waited for about 10 minutes till the dog went somewhere. After that I've been to Greece about 10 times and haven't met any stray dogs. But everytime I pass any buildings in villages I take a look if the dogs are closed (had this situation on Crete and Kos this year).
Came across this thing now (it's a virtual dog whistle app in polish) but haven't tried it: https://play.google.com/store/apps/details?id=com.greatapps.dog.whistle
I still think of some REAL solving for such problem. I wanted to take a pepper spray (legal in Poland) with me but...it's illegal here so cheers to the typical Greek paranoia...
also, sorry, no children's books. closest I might come is an illuminated manuscript about different loves told through mythologies I invented. yet it too is incomplete. https://www.amazon.com/My-Love-Chapter-Leon-Sandstone/dp/1703412168
I usually take a look at https://www.windy.com before going for swim anywhere in Crete. The info is usually accurate even days before visiting. It is common to have great differences in the wind even for places close to each other.
Yeah, some people don't issue receipts to avoid taxes, so paying by card is an issue for them since they cannot hide the transaction. But it is mandatory from the law to have a POS in any kind of store so don't worry. If you encounter anyone that says he doesn't have or it doesn't work then either tell them you can't pay in any other way and to try once with the POS or just ask them to issue a receipt and see their response.
You can use the BEAT app to order and pay for taxis through your smartphone.