Hi Alain,
From a tourist’s perspective, I’ll add that drivers here tend to stop pretty much anywhere (to drop someone off, run an errand, chat, etc.), and stop signs are often replaced with yield signs (I even wondered if our "stop" signs exist in Greece at all 🤪). But overall, driving feels pretty relaxed, I think.
As for extra insurance, I never get it—my credit card coverage seems to be enough (I’ve tested it twice over nearly 20 years with two different banks, but only for small amounts, and it worked out fine).
Si tu diffères de moi, mon frère, loin de me léser, tu m'enrichis (Saint Exupéry)