Quadcopter PID, please help!!

Hello everyone,
I'm trying to make a quadcopter with Arduino.
I already have the angles (roll pitch and yaw) thanks to an IMU. They are in degrees and filtered with a complementary filter.
I want to apply a PID algorithm for each axis but I dont know if the inputs should be angles (degrees) or angular velocities in degrees per second so as to calculate the errors with respect referencies.
Which will be the difference? Which will be the best way?

Finally, another question about a PID code: I have seen that many people don't include time in their codes. For example, their derivative term is kd×(last error-actual error) instead kd×(last error-actual error)/looptime and something similar with the integrative term. Which is the difference?

Thank you in advanced.

RE: Angles vs Angular Velocity

To keep the quadcopter at a specific set of "Angles" ( Roll, Pitch, Yaw) , I think, you will need to input the Error between the Measured Angle and the Requested Angle into the PID function.

RE: "looptime"

If the PID is called at regular intervals then ...
the "looptime" can be buried in the Ki and Kd constants.

If the PID is called at irregular intervals then ...
you could include the "looptime" value directly in the PID calculation.