I thought the idea sounded interesting, but it appears to be very narrowly focused on the problem of "I'd like to write something in [German], but I don't know [German] all that well". I'm more interested in the problem of "I'd like to read something in [German]". The "right way" to solve the problem of knowing how to write something in German is, unfortunately, to read several dozen examples of people writing similar things.
Dictionary entries are complex things. (Well, often they aren't, but they should be. The amount of information one dictionary entry needs to provide is quite large.) I don't see a lot of value in having the editor pop up abbreviated dictionary entries for words that I know I need to look up. If I know that, I can look up the word in a high-quality dictionary and benefit from a much fuller entry.
Dictionary entries are complex things. (Well, often they aren't, but they should be. The amount of information one dictionary entry needs to provide is quite large.) I don't see a lot of value in having the editor pop up abbreviated dictionary entries for words that I know I need to look up. If I know that, I can look up the word in a high-quality dictionary and benefit from a much fuller entry.