CBD oil is not legal in all 50 states. You should see the shitfest that is going on in my old homestate, Indiana. A lot of the heavily religious indoctrinated states that have no separation between church and state will fight it tooth and nail until the end of time.
In regards to getting a medical marijuana card. It's nice to have for the legality sake, but I still deal with the black market as they aren't adding in the costs of overhead, employment wages, trivial packaging costs, and their own personal opinion on what "retail" marijuana should cost.
I have not been to the CO scene yet, but I'd love to check it out. Maine has a wonderful program, but it's slowly being dismantled as they are now trying to figure out how recreational/medicinal laws and programs will coexist.
I made a cursory glance at an article that said it was legal in all 50 states but come to think of it if I remember correctly, and it's entirely possible that I'm not, I think there was something about Indiana having a problem with CBD oil.
Too bad about Maine. I imagine that inevitable transition from medical to recreational creates that problem for a lot of states. CO is outstanding from what I gleaned from my recent visit. I gravitated to the edibles because they said smoking in public is not permitted. We were staying in a hotel and didn't think the reeking of that skunky stuff would go over very well with the hotel.
With whether to go with the card or the black market I totally agree with you. Where I live it's the policeman's call whether to arrest you or just give you a fine nowadays.