Re the systematic racist bias in 4. - since you postulate a world in which 100% of terrorists are muslims, why would anyone non-muslim ever be investigated for terrorism? (whether with 'gusto' or not)
Research says drug usage rate is similar for black and white people in the US, but prosecution and conviction rates are not[1]
1. http://www.hamiltonproject.org/charts/rates_of_drug_use_and_...
// Assuming the police are not incompetent, of course, which may not hold in your hypothetical world where they investigate non type X people for terrorism even though they commit zero percent of terrorist attacks - probably out of some misguided diversity quota or affirmative action policy, I assume? ;)