I live in Retiro. It's one of the safest places, as far as I'm concerned, around the Micro Centro/Recoleta/Tribunales area.
It depends on where you are looking in Retiro (more about that below). It's no different from Recoleta - the same distance from the Villa (and the beginning of Palermo's on the outskirts damn near), but there is a police station with a good police presence in the area and a lot of political stuff (not so much Argentine, but international). The MercoSur headquarters, the Foreign Relations building (in Palacio San Martin), the French consulate, the site of the Israel consulate that was bombed, etc. A lot of chic art galleries. It's actually quite an affluent area.
There are two parts to the official Retiro neighborhood. Our side is on the other side of Alem from the Retiro train station and the villa. It's bordered by Libertador/Alem, Santa Fe and Peligrini/9 de Julio. On the other side of Alem and the train station is the really, really dodgy part of Retiro, but it's a different world.
There was the French tourist that was killed in broad daylight in Plaza San Martin some months ago. That happened on the Micro Centro side of Plaza San Martin, near Alem, which is getting close to dodginess anyway and is literally one edge of the barrio.
You need to look more at renting here though - it will not be easy for you to find a "1 year contract." There are either temporary or long term contracts. Temporary contract terms are limited by law to 6 months. Doesn't mean someone won't rent a place for a year, but they're not supposed to.
But possibly the biggest hurdle to renting for a year is the temporary market here. Apartments are sometimes booked a year in advance, though they may not be full up. They are almost certain to have some booking, at some point during that year, which makes it difficult to make that kind of deal in advance.
Long term contracts are by law two years and give a LOT of rights to occupants. So much so that the vast majority of owners require some form of guarantee. Most commonly it is the deed to another property in Capital Federal, but sometimes (still difficult to find) people can work out something like paying half the entire lease, or the entire lease, in advance, in addition to security deposit and such.
Living here is not easy. Make sure you get all the facts on your fact-finding tour!
There's a lot to think about, particularly right now.