Marijuana should be legal for “recreational” purposed nationwide, with reasonable regulation befitting a substance that, used in moderation, is basically a mild euphoric with real but generally quite moderate side effects. I’d tax it at levels similar to alcohol, perhaps a bit less given the lower social costs compared to alcohol abuse.
And as far as cannabis-based medicine goes, it should be legal for medical providers to prescribe cannabis or cannabis-based medicines for any bona fide medical condition for which it has been shown to be effective. Whether it’s the best treatment for an individual patient should be up to the doctor and patient, within the normal bounds of professional practice.
I would argue for this medical cannabis to be tax free (as an incentive for people with bona fide medical needs to go the supervised-by-a-doctor route rather than self-medicating with recreational product), and for it to be covered by insurance for any conditions where it is likely to work as well as, or better than, other available treatments, and/or with fewer side effects.