Forget about it being tax free !!!! The planet is in recession, so cmon TAX it make growers have licenses, create jobs in all aspects of growing through to quality control. Its not like MJ or any other drug are difficult to aquire. So let's stop all the gangsters and people smugglers running the show. Make it legal and let democraticly elected governments reep the proceeds and get the global economy moving.
The world is in recession because there's not enough money going around, every country owes every other country, which in turn owes the banks... Taxing cannabis will not "put more money into the system" because there's just no more money to go into the system, unless the banks print more, which will only degrade the current value of a dollar (Inflation), which will only put the countries that received this money into further dept.
No "Job Creation" is going to fix a self destructive economy...
As for who should have more rights... it's simple.
If you don't have the issues that opiates help relieve, than you cannot have opiates, their illegal.
Medication that is prescribed, unless you are the one whom it was prescribed to, is illegal to possess.
Now, with MMJ, I believe that those who use it for medicine, to relieve themselves of pain, induce hunger, or whatever it is that they require it for, that a recreational user does NOT require it for, should have not much more rights, but a small handful of additional rights, such as medicating outdoors (not in parks and such, keep it similar to tobacco requirements in terms of where) or increased possession amounts.
I believe the NEEDS of people should always come before the WANTS...
THIS IS NOT TO SAY I DON'T THINK EVERYONE SHOULD HAVE ACCESS!! BECAUSE THEY SHOULD.