I use both the pitch bend and modulation wheel a lot. They are essential to me in order to properly imitate intruments such as guitar, sax, fiddle, steel guitar--almost all of them.
It's another reason I can't do much left hand manual bass. I need to have that hand available for the wheels. I hit the chords and let the Hold feature keep the style going until it's time to change.
I use the Modulation primarly for vibrato and it is even more valuable since the PSR2000 does not have aftertouch. I could probably do without the Mod wheel, but certainly not the Pitch Bend wheel.
DonM