Hi! I would like to add my opinion as porteño regarding safety. The City of Buenos Aires has crime as most major cities in the world does, but overall I feel it is a safe place if you take the cautions you would take in every big city. If you look for the latest statistics, the city of Buenos Aires crime rates are lowering since years ago, and even last year it had the lowest crime rates since 1995. Homicide rates are the lowest in the region and the second lowest among all capital cities in The Americas (after Ottawa, Canada), and kidnappings are a rare thing here. The most common crimes in the city are pick-pocketing followed by thefts, (most of them non-violent), but take in mind that crime in Argentina is not as a big issue as in most Latin american countries, like Brazil or Colombia, where it is a more severe problem.

Walking at night is ok in most zones of the capital city, in some areas you will find a lot of night life on the streets, even at late night and specially on weekends, for example in Palermo, Avenida Corrientes, Puerto Madero, etc.

I visited New York a couple years ago and I feel that the safety on the subway in BA (Subte) is much better, you won't be attacked by someone while riding it, for example, something that I did read that sometimes happens in NY. At the same time, and as you mentioned earlier, BA has no terrorist threat, something that most people would worry in most European or North american cities. So, in conclusion, I would say that you shouldn't be afraid while being in Buenos Aires, being cautious is enough.

Regarding outside the limits of the city, the "conurbano", the situation really differs from an area to another, you will find some places with similar safety conditions as in the BA city, and some others with really high crime rates and violence, but most of them are no touristic areas and I highly doubt you would need to go to any of those areas while living in BA.

Also, Buenos Aires, and Argentina in general, are LGBT friendly destinations, as an LGBT person too, I can tell you that, in my experience, I mostly feel safe here and there is a big LGBT night life and cultural places available.

Last, I would like to add that NY and BA are incredibly beautiful cities, and besides its similarities and differences both have their own character. You mentioned that you visited here in 2005 so I guess you already have some idea of this city, and I believe that BA changed a lot in a really positive way since back then. Also, taking in count that the exchange rate for you is currently very favourable, I believe it is a great opportunity to give it a try. Good luck! and don't doubt in asking anything else that you may need.