I support Araucaria's suggestion, albeit with some degree of uneasiness. To me the most important aspect of English Language & Usage as a resource is that it provides searchable, archived answers to language and usage questions that visitors other than the original poster may find valuable.
Single-word requests, phrase requests, and idiom requests all involve a questioner's posting a definition and asking for the term that best conveys that meaning, or providing a sentence with a blank in it and asking for an appropriate word or phrase to complete the sentence. For the poster, the answers are undoubtedly useful, and for answerers the questions resemble name-that-word vocabulary quizzes or trivia challenges—they're fun and not especially research-intensive.
But the value of these questions and answers to future site visitors is severely limited by the fact that they amount to a collection of reverse-dictionary entries. Their accessibility to future visitors depends on the visitors' happening to search for the same word or phrase that the original questioner supplied in describing the definition of the wanted word or phrase.
To me, the central question is this: If each such question is primarily of interest to one questioner and (temporarily) to a bunch of prospective answerers, doesn't it make sense to ask and answer them in a place that is explicitly dedicated to that particular type of entertainment?
Like most other EL&U participants, I try to answer single-word requests from time to time. I recognize their popularity and intellectual appeal, and I recognize their practical use as a gateway to acquiring reputation points relatively easily. Indeed, the strongest argument I can think of for retaining SWRs, PRs, and IRs on this site is that the relative ease with which new users can parlay them into reputation points may provide an important and continual infusion of new blood (in the form of people with newly acquired privileges) on the site.
But from the perspective of practical value to EL&U in its role as a reference tool, the cumulative effect of these requests may be quite harmful. If you are using EL&U's internal site search to hunt for a discussion of how a certain word is used or where it came from, it is counterproductive to have to wade through a bunch of chance occurrences of the search term that arose in the context of SWR suggestions. Questions with little or no intuitive lookup value gum up search results and clog the archives with what amount to false positives.
I don't see this issue as involving the salvation or destruction of EL&U, but I do think that if we want to improve the long-tern usefulness of the site as an archival resource for questions that have significant staying power, we ought to consider whether spinning off "name that word" and "fill in the blank" questions to a Stack Exchange site that specializes in such questions might be beneficial.