I've been a fan of .013 on acoustic for a long time now. Something about that extra tension makes it louder and woodier sounding.
Was the guitar maybe intended for nylon strings? I learned to play guitar on an instrument that had steel strings, but was intended for nylon strings. Jeez, the action on that thing was like 3/4" off of the fretboard at the 12th fret. At the time I didn't know any better, and it tore my fingers to shreds. The first time I played an electric with more reasonable action, I was amazed.