Saying "Nicaragua" is a lot like saying "California". There is a big difference between Managua, Masaya, Granada, EstelÃ, ... For example, I don't like cities so I would not move to Managua but I also would not move to Los Angeles. I would say however, that Managua is less dangerous than Los Angeles.
Political stability is a non-issue. While Latinos talk more about this, Nicaragua is quite stable. The main difference is that in the US "how it works" tends to be reserved for a select few whereas everyone knows here.
Anti-usano attitudes are few and far between. You can, of course, encourage them by presenting yourself as being superior. But, if you treat Nicaraguans with respect, you will get respect back.
That's a good start. You might want to check out NicaLiving.com as there are lots of members living all over Nicaragua. i happen to live in the mountains near EstelÃ.