It looks like in some cases it might be useful to have ability to use something like "find and replace" in question bank (probably limited by category).

One use case for that is translating many similar questions to another language (then one would be able to find the repeated string in one language and replace it by its translation). However, there are other use cases, when one decides to reword many similar questions in a similar way.

Perhaps at first it would be sufficient to have such ability for "Question text" (especially useful with Embedded answers (Cloze) questions).