fortissimo is just playing loudly. i cant really remember exactly what it means, but it could be "very loud", (going from mezzo forte, forte, fortissimo, which is roughly fairly loud, loud, very loud)
and allegro is just playing quickly.
which im sure you can do on any patch on the microkorg (possibly some patches dont have adjustments for velocity but id assume almost all do)
id also guess that you know what they mean and are pulling the "guitar teacher? i dont need no teacher i just play what i feel, man" lines.