Right. It's harmful like marijuana, which clearly causes no parallel effects to cigarettes like elevated pulse, vasoconstriction, altered state of consciosness, and has no chance of causing addiction or of introducing naturally carcinogenic chemicals to your mouth and other respiratory passages.
Citation needed, if you can find one without conflicting evidence. Does not cause addiction. You don't have to burn it and inhale it. Used by elite athletes the world over, before, during, and after competition. Is actually considered a performance enhancing drug in some sports (still not allowed).
By far the stupidest argument that you have made here is that marijuana is often laced with other substances. No one would ever lace MJ with PCP. They would just sell the PCP and then sell the MJ. There is no reason for someone to lace your weed with anything unless they were trying to personally poison you, and then all food is suspect.