1. Yes, but since the body has had time to store the metals, cheers for Wolff Chaikoff, removing without true chelators means more GSH depletion, your primary defense against prions and crystaline bio-weapons like Brucella:
2. No
3. No, read up on my methylation rant. B vits need to be methylated into higher forms one of which is 5-htp, if an enzymatic pathway is broken due to Hg or Lead you can't do that.
4. No, when you make your own it becomes ineffective
5. DMSA, specifically frequent dose DMSA