I would appreciate some opinions on the use of cannabis in medicine. If it were legal, would you prescribe it?

Not in current form. It is legal in some states, at least at the state level. The way it is currently handled, it is not medical in any way. There is some great research into the cannabinoid compounds with many potential benefits for pain, mood, bone health and even addiction to name a few. However smoking a plant that is harmful to tissue such as lungs and heart and dosing is not regulated is not medicine.
Opinion. It is legal in several states and prescribed quite commonly in them. I think we're wrong headed about cannabis, because it is being prescribed for almost anything and in any intensity. Particularly with pain issues. We need more research if we are going to so willingly offer this treatment.
Tremendous. I do not have enough characters to discuss this, but currently physicians can only recommend. Marinol was a THC prescription pill which excluded the medical benefits of cannabis. Cannabidiol is currently the most therapeutic component of cannabis. If your state is medically legal, I suggest you consult that physician. He or she may help you.
It is illegal. Cannabis is illegal by federal law, although some states have set conditions to legalize it. Federal law though trumps state law. There is research under way for medical prescription of cannabis.