I'll start
workshops can't be set to give to and take from the same stockpile. links between a workshop and a stockpile (or a stockpile and another stockpile) can only go one way
water source zones need to be set on tiles adjacent to water, not on the water tile itself
marking a door as a forbidden item does not make the door "forbidden" in the sense of being impassible. your dwarves will continue to walk through it unless you open the door's status page and toggle it from "passable" to "forbidden"