BTW there's a little "bug" if you want to call it like that: Conventionally, the level editor allows to place an item right at the camera position. However, I altered the value of eye_height (or similar) in the last minute, to get the right eye height in walk-mode (in the editor) and didn't notice that a placed item will now be positioned slightly under the camera. You can alter the source if this bothers you, simply divide that eye_height variable value by 2 (because I doubled it), then it should be fine again.
This was always the way the level editor (aka interior dropper) used to work: you just walk trough (or fly trough) and drop stuff where-ever you stand (by ctrl-V, or RMB>New>File ... load mesh or sound etc.).
I remember, back then such a plain first person perspective editor was quite uncommon, if not new.