I have pretty much the same story (but 4 years) and lived in Sonora and Nayarit. I have close friends living in Sinaloa (expats of 20 years).
I now live in Guanajuato, and the only crime I've heard of first or second hand in the years in mx was a worker taking some cash which was laying around, and some gringo's stealing from each other.
On the other hand I lost three friends in hurricane Odile, so I guess don't forget nature can be a much bigger threat if not given enough respect.
I realise this is a bit of a late comment and you might miss it. But is there any way to contact you? As I mentioned earlier in the thread, I am married to a Mexican woman and I was wondering what it is like to live in Mexico as a European (Specifically software engineers, which you might happen to be as well ;-) )
The places you listed are all the safe states, which effectively is a different country.
It's not super complex, the states near the Gulf/Yucatan are generally the safe ones.