The article I cited reported that breast fed infants wind up getting up to 1000 times as much aluminum from vaccines as from diet. That is the empirical result that paper was reporting. The rest is window dressing which would be at best the authors opinion. The question of whether getting that amount of aluminum is toxic is more complicated. The natural experiment is to scale it for weight and inject it into post natal mice. That experiment has been done and reports they suffer great developmental damage. There's also a fair amount of epidemiology that bears on the subject, which also suggests the aluminum is causing damage. Its highly correlated with autism, for example. I reviewed the literature all with links to about 3 dozen citations at http://whyarethingsthisway.com/2014/03/08/example-1-pediatrician-belief-is-opposite-the-published-scientific-evidence-on-early-vaccine-safety/
Also, I suggest to you that there is demonstrably very strong crowd think effects on the subject of vaccines. A phenomenon of crowd think is persecution of heretics. In such a climate, scientists publishing results that challenge the orthodoxy have to tread very sensitively indeed if they wish to avoid the inquisition. And they often respond to this by adding various flowery prose to their publications such as that which you mention, mitigating the distaste of having to report such contrary results. If you wish to understand crowd think better, I recommend: http://whyarethingsthisway.com/2014/03/22/why-are-the-pediatricians-so-confused-about-the-actual-state-of-the-scientific-literature/
There's no "inquisition" in medicine. There's peer review to ensure you did your homework, and government agencies to ensure you don't hurt (too many) people.
window dressing which would be at best the authors opinion [...] various flowery prose [...] mitigating the distaste
What criterion are you using to select what counts as fact and what is immaterial? How would you identify an author who is being reasonably cautious not to make any unjustified statements?
For example, what would be inappropriately off topic to post to LessWrong discussion about?
I couldn't find an answer in the FAQ. (Perhaps it'd be worth adding one.) The closest I could find was this:
However "rationality" can be interpreted broadly enough that rational discussion of anything would count, and my experience reading LW is compatible with this interpretation being applied by posters. Indeed my experience seems to suggest that practically everything is on topic; political discussion of certain sorts is frowned upon, but not due to being off topic. People often post about things far removed from the topics of interest. And some of these topics are very broad: it seems that a lot of material about self-improvement is acceptable, for instance.