On Page Assessments, you need to fill in either the WikiProject field or the Page title field before clicking Search. There's no use case that would require just searching for a namespace without WikiProject or Page title.
When a user clicks Search without filling in at least one of the other fields, don't run a query. Just display a red warning: "WikiProject or Page title field required"
Also make sure that the results are ordered alphabetically.
Also, this will probably mean that we don't want to have the page do a default query at all when you first load the page.