Hi tejano, jer here. Welcome aboard the Spain forum.
Indeed the [URL=http://www.multimadrid.com/descrips/sites/info/metro.htm ]METRO[/URL] stop called Retiro is one and the same. It would normally be your best bet but keep in mind that this summer (until Sept.) that line (line #2) is closed for renovation between the stations of "Banco de Espa�a" and "Santo Domingo" which messes up your plans a bit since you will only be able to go in the other direction (towards the "Ventas" stop). Click
HERE to go to my detailed post on the Madrid Metro closings for the summer.
On the other hand, if you look at the next map up on the Soft Guide site at
http://www.softguides.com/madrid_guide/maps/m1p4.html (their maps are great!) you will see another METRO stop called "Vel�zquez" which has the number 4 line and is open for business as usual

. It will be a bit harder to get to the center of the city (the
Puerta del Sol for example) and you will have to change lines but thems the brakes.
As for the safety of the Madrid Metro, there are floating hands all over the world but if common sense prevails, all will be ok. The Metro here is (in my opinion) the most efficient and extensive in the world and is very safe, even at night.
So, occasional closings are the price we have to pay to have such an AMAZING METRO system.
Have a great trip.
Saludos and hope I helped,
jer...
p.d. The Madrid Metro website (in English and Spanish) can be found at
www.metromadrid.es