The person to ask about dosages and interactions is your Physician or, if that is uncomfortable for you, your Pharmacist. The interaction can also vary from person to person.
I think all of your questions and threads should be best addressed by one medical professional who is familiar with you and your need for pain control.
My husband had a multitude of medical problems and the only way he could be treated adequately and safely was to have one Physician aware of all of his problems and prescribed medications in charge of his treatment.

