Sure. I've worked with editors before. Pretty much everything from Bethesda has come shipped with either the TES construction set or GECK lately, and the same was the case for all of Blizzard's RTS games. They have the basic engine of the game pre-made for you and let you construct levels, a plot, scripted events and so forth within that engine. It's the tool that you use to build a game within a given engine.
The reason I'm uninterested in this project is that the engine you're designing for your editor is not the sort of engine that I would use for a roguelike. Having attributes, skills, an action system, a notion of items and so forth are all good ideas, as is having an over world map as your basic method of travelling around (rather than having a nethack-esque slog through emptied levels), but a lot of the things lower down on this list are either irrelevant to good roguelike gameplay (detailed change item quality over time, quests, dialogs, dynamic text) or actively harmful (detailed internal structure for each creature, hardcore materials simulation, procedural world generation, seasonal changes).
Maybe it's just a different design philosophy, but I've always thought gameplay should come first - come up with an interesting mechanic, pick an engine that can handle it, code that mechanic in, then build a game around the result. The success of Portal isn't because of the engine they used - the fact that I couldn't name which off the top of my head shows that - but rather that they had a unique and innovative mechanic for people to play with: the portal gun. You see the same thing with Prince of Persia and the Time Travel mechanics, with destructible environments on Cataclysm: DDA and Caves of Qud, even with unique car driving mechanics on DDA.