One thing to keep in mind, most of these stuff are relative to what your proposed intervention. Minor issue justifies minor intervention and lower cost; major issuse will demand major intervention and higher cost. As long your proposal is in line with this relation, it is still acceptable. Therefore, strictly speaking, there is no issue that does not deserve a solution.

Judgement of whether it is clincally significant is subjective. Concrete numbers are more convincing.

Prevalence is only relavent when its impact on individual is meaningful.