I lived in Curitiba for more than 1 year and I lived in around 4 different districts because I shared apartament with strange people and when I did not like I moved on to live in other places.
Curitiba is a very beautiful city and the cost of life is not high and the best and safest districts to live in Curitiba are:
Agua Verde
Batel
Jardim Botanico
Cabral
Boa Vista
Merces
Bom Retiro
Centro Civico
Please do not live in downtown of Curitiba because is dangerous and do not live in Sao Francisco district. and avoid going alone to cities close Curitiba like: Sao Jose dos Pinhais, Colombo, Cidade Industrial , Araucaria ... because are dangerous.... Be careful! I hope you have a car in Curitiba.
Many people from Curitiba are very reserved, cold and impolite! Be careful when you choose your friends there!
Look for christian people for friendship. Many women in Brazil are jealous, competitive and fake.
If you have a wonderful boyfriend/fiance/husband some women will try to rob him from you..... Be selective!
Avoid talking about your success, plans and achivements for strange people, because They can use it against you.... Jealous people!
Be careful
Regards,
A brazilian in Usa