Veer Jee, Naam has a power that we as are mere mortals cannot even begin to understand. If you read the translation of Jaap Sahib, all those qualities, Naam posseses. I'm sure Gursikhs can tell you many stories of seriously ill even dying people being healed by Naam, believe it or not, it happens. As for the world, that's up to Guru Sahib and in his hands, not for us to worry about, we can only do our best to follow Guru Sahib's teachings (which does mean serving humanity and being caring, but not about the world itself). Ok fine, you're smoking Cannabis now because you are genuinely using it for a medicinal purpose, but if you go on using it throughout your life (even after having taken Amrit) under the pretence of medicinal use (my head hurts, or I cut my finger oh let's blaze one up, to "keep going" for a school paper) you're only fooling yourself.I would also recommend you read up on Nimrata (humility) as well as Ahankar (ego).
Oh, I was just curious, are you putting tobacco in your joints? Because if you are, that is totally not allowed in Sikhi medicinal or otherwise.