Something doesn't have to visibly run in families to have a strong genetic component. I mean, there is solid evidence that PTSD has a strong genetic component, to the point it's commonly discussed with regards to genetic predisposition, but obviously it rarely runs visibly in families (though some suggest it may be part of why addictions run in families/communities).
Most chronic conditions listed have genetic predisposition and environmental factors (age being a major one for most of those listed). With autism, there have been links made to air pollution (with some caveats and some leaning more towards in-utero exposure over child's direct exposure though those often overlap) and some questions have been raised about maternal diet and lifestyle during pregnancy possibly raising the chances with a child who has a raised genetic risk. Even with knowing a lot of the risk factors in many of them - like genetics or overtraining in children is a risk factor for arthritis later in life - it's always a factor, it's never a guarantee.
Has anyone who believes they are safe actually read any literature, studies, medical journals, peer reviewed studies to suggest otherwise?
Yes, as a previously "delayed vaxxer" who now has paid to get additional vaccines privately for my kids, and also works with journals regularly, I have read quite a bit of the literature on it. Here 's one such article from 5 years ago that discusses the benefits and risks of components in recent vaccines pretty clearly, I think. Anything reputable on it will discuss the risks, but having risks doesn't make something not generally safe. Safe is always relative, even the 'stay at home' which is generally perceived as very safe has the risks in some to increase Vitamin D deficiencies, deconditioning health risks, and certain types of injuries before getting to interpersonal risks.
Also, please be aware that "non-fiction" books are very unlikely to be fact-checked by anyone but the author unless the author pays for it out of pocket themselves. The industry puts the entire liability for on the authors are rarely pays out for anything beyond basic copywriting consistency. It's an issue that has bit some authors in the butt and others have fought for better. We also have an issue with replication crisis in peer-reviewed journals across disciplines so that's always something to double check.
Speaking of, while I can believe general medical time on this is low - it seems like a specialty topic - I'm struggling to find a reputable source on pharma reps teaching courses at reputable medical schools (though actual pharma reps generally need specialty degrees themselves).