UPDATE for anyone else who might have a similar situation
- I received clarification by Greek Police HQ on what is legal and what is not:
Reporting of suspected breach of quarantine regulations - to "contact the General Secretariat of Civil Protection, through the respective site on the internet." How I understand it works is that they collect the complaint/information, then the police acts on it.
Re CAR DRIVES - "It is only allowed to drive on a permanent residence, without return" (this is about a place being the address registered on e1 form) and "only for specific reasons" (category B permit)
+ " if you suspect that there are people who drive from regions in which are registered deaths by coronavirus [eg Rethymno town], you do call the police so as those people be controlled. We would like to inform you that the law doesn’t allow these people to move free"
Re GATHERINGS -"It is not allowed for people to gather in groups, UNLESS they are members of a family AND live all together, AND doing this into their house."
Re OUTDOORS activities - "only allowed for to go out for physical exercise or with their pets, on a daily basis, " individually or per two persons, keeping the distance of 1.5 meters from each other."
+ BTW, NOISE during "summer (01/04 – 30/09) 15.00 – 17. 30 and 23.00 – 07.00, winter (1/10 – 31/03) 15.30 – 17.30 and 22.00 – 07.30)" is enough reason to call the police apparently