Well, the truth is, I don't know. So I won't pretend to have a definite answer to either of your questions. We all keep learning, sometimes acquiring contradictory information, which we have to evaluate and reconcile with what we already (think we) know.

I wasn't familiar with the heavy-metal absorbing properties of spirulina, but knew that mushrooms do the same thing, so I'm not surprised. About kombucha, I knew it had alcohol, comparable to any bread or yogurt. That's what I also tell my customers. But the amount is so minute that children and pregnant mothers can drink it without adverse affects of child development.

Of course it's up to each one of us what we want to put into our bodies and what we don't, but in my belief (not founded on research) there is something that can be just as bad as lead, strontium, phosphoric acid etc. which is the worry. I think even if we go to the most remote part of the world, we can't escape the micro and macro-toxins that are pretty much everywhere by now. So let's not let the worry bother us!

Instead of escaping the many poisons, we could just accept the fact that the air we breathe has tire-dust in it, the water we drink is not unleaded, and the food we eat is laced with chemical weaponry. What we can strive for, which is what I do and recommend, is to keep these things as low as possible by keeping things diverse without going into excess. With this I'm not saying you are wrong for being selective and exclusive, it's just my own way of seeing things.

By the way, as far as I know, spirulina IS a cyanobacteria, which commonly is called a "blue-green alga," similarly how the kombucha culture is often referred to as a fungus, even though it's mostly bacterial, with yeast being the only fungal part in it.