I microwaved ramen noodles for three minutes even though it said on the Styrofoam that it shouldn't be microwaved?

The hot liquid can deteriorate the styrofoam in the cup...but doing it a time or two won't kill you.
The acid from a lemon can eat right through the styrofoam, so you shouldn't microwave tea with lemon...and if you do it long enough you'll probably have tea all over the inside of the microwave.