Irrlicht has quite a few editors for it however the "official" one is IrrEdit (http://www.ambiera.com/irredit).
I am quite a fan of Irrlicht because it provides a good amount of functionality to get you started with 3D and C++ and once you "grow" past the convenience functionality, you can easily replace it. It is also very portable to different operating systems.
Personally I would call it a games engine because all of its default functionality (i.e addCameraSceneNodeFPS, collision, BSP support, etc..) really is geared towards game development unlike Ogre 3D which doesn't really provide much out of the box.
My issues with it.
1) The CollisionResponseAnimator in theory provides everything you need but is buggy and frame rate specifc. A massive missed opportunity so you will have to write your own (can be tricky if you are starting out).
2) It enforces it's own memory system (assuming because it was pre TR1, shared_ptr etc...?). It would be much nicer to leave the memory management to the native C++ system (RAII).