solidarity means solidarity. other working class people are not your enemy (re: 1984). the all or nothing mindset accomplishes nothing besides closing your mind off to the plights and perspectives of others.
not within your lifetime though. you just have to have faith in the peer review process. also peer reviewing typically does not involve actually reproducing the results
but you can't! are you personally able to verify the results of every scientific investigation ever performed? think about what's currently happening in psychology. loads of old foundational studies have been found to be irreproducible. and yet people had faith that they were conducted honestly and appropriately
that's not true. there are things that are not definitions. like my bed for instance, there are aspects that are arbitrary (my personal preferences, design choices, etc) and aspects that are not arbitrary (its physical form that exists beyond definition)
yes but translation from evidence to what caused the evidence to exist requires assumptions, like the fact that trig works. I'm not saying assumptions are bad, just that they should be acknowledged
it's about how many people didn't vote. that's literally it