I know it's bad for guitar speakers to play a bass through them, but are the frequencies safe if I play an electronic drum set through them?
If you burp, fart, and sneeze at the same time; you will die.
I have no idea, but I wouldn't try it if you don't wanna' hurt your amp.
"Breathe, breathe in the air
Don't be afraid to care"

Fender Strat/Tokai LS80>few pedals>Orange Rocker 30
It shoudl be fine... Just plug the electronic drums into the Effects loop return so that the preamp of the guitar amp doesn't flavor the sound at all.
No, bad experience with this.

If the eq is messed with on the drums, youre fucckered