my question is this, since the custom attributes appear in the curve editor, can i expect them to behave as a normal channel would? So far my experience is that this not the case. if you apply any of the looping "param out of range" curves to the an animated custom attribute channel, the result is wrong. any suggestions as to how to work around this?
The Inverse Kinematics solution, by default, is set from frame 0 to frame 100. You have to increase this value to have the solution to solve for longer animation. See Inverse Kinematics_Rollout_Interface in the reference material.