Its mostly covered in the formal logic section of the foundations. Bridge wrong way is "the oldest mistake in the book" or something like that

The missing assumption in the argument is whether relying on quackery = doing more harm than good (intuitively this feels obvious but ofc with LSAT you can't bring in any thinking like that). B draws the two together:

"People who attempt to diagnose their medical conditions are likely to do themselves more harm than good unless they rely exclusively on scientifically valid information." Unless = negate, sufficient so

/rely-exclusively-on-SVI -> likely-to-do-more-harm-than-good, or rephrased in context

rely-on-at-least-some-quackery -> likely-to-do-more-harm-than-good

E is similar but is the oldest mistake in the book (harm -> quackery, not quackery -> harm)

I thought the same thing. Re-reading, though, it doesn't say its required to establish knowledge in order to charge the person (only that its an element). I think in the real world we know this is how laws work, but you can't say this for sure just from the text

This made it click for me, thanks!!

Some of these are hurting my head because I feel like the contrapositive just isn't true. E.g.

"Where the environment is protected, biodiversity is preserved." Makes perfect sense, sure. Then, you take the contrapositive and get "Where biodiversity is not preserved, the environment is not protected." But, what if the environment was protected, and biodiversity just crashed for a different reason (e.g. the weather or something), this feels intuitively like the contrapositive doesn't always follow in a valid way to me.