I'm glad you are not a troll JTankers, but the "estimate" you cite is not an actual argument. It goes like this: "I include chaos theory, in some completely unconstrained and unexplained way, and I get that the usual timescale estimate of 50 million years becomes 50 months". That's not going to cut it, even for someone who has some education into how estimates work. The estimate is still only as good as the argument that leads to it, which is:
1) a micro black hole can be created (an unknown claim, yet is cited at "10 percent likelihood" somehow)
2) even though most such black holes will move at near c (a point you have yet to acknowledge, interestingly, as it is was the core of one of your arguments), every now and then you might have one at less than 11 km/s, and get caught in the Earth's gravity (no estimates made of how likely that would be, only that the vastly more numerous cosmic ray events don't count because they are not having head-on collisions with other similarly energetic particles)
3) if that happens, "chaos theory" magically tells us it will accrete the Earth in 50 months, not 50 million years as in other estimates of this process.

Now, I'll grant you that even if a more likely estimate is 50 million years, we should not be partaking in actions that could destroy the Earth on even that timescale. The real issue is, why are the new energy levels suddenly going to start making black holes that are different from any that have already been made, and why are they going to be moving at less than 11 km/s at the higher energies than at the lower ones?

I agree that one should have an idea what the risks are of one's behavior, but it is all too easy to just make believe risks and say "but you can't prove this isn't a risk, can you?" I'll bet you drive a car. Can you prove that there's no risk you'll run over someone's little baby, even with all the precautions you can take? How can you get into a car if you can't prove that you won't do that? At some point, we have to be able to say "I can't worry about remote risks, it is enough that I not be cavalier about the real ones that surround us all the time."