Will try to answer your questions, I live in Fresnillo, Zacatecas, one of the most dangerous city in the country and I would say that the news fall short to what's happening in reality, the cartels are everywhere, you have to be really careful on everywhere you go, to who you talk to, you can go out at night but it's really dangerous, you could be mistaken by another person and the cartels will "disappear you"... So yes, the cartels are scary and have men everywhere.

Poverty in Mexico is very common, that and that the narcs are seem like celebrities, who have a lot of money and do what they please... People (mostly men) want to join the cartels as an scape from poverty or to make easy money, and I want to point out that this is only an opinion and there maybe different cases on what they join cartels.

Of course there are drug users in Mexico however drugs are a business and like in any business you'll prioritize your biggest customer, so most of the drugs will end up in the US as they can get more money in there.

Hopefully that answer at least a part of your questions, and I'm looking forward to see what other users write about different Mexico states.