Along with the other parameters you listed that would matter, its also important *how much time the LEDs stay off* between their 1.5 ms on state; the time they get to catch their breath, so to say. As long as this duty cycle is small enough the design should work fine even at 5 volts. I say this on the basis of a 4 digit 7 segment display I have integrated in a product; no resistors, running 22X7 the past 8 odd years, and no failures...yet.

Regards,

Anand