I'm very much the poster boy for neurotic/OCD-like behaviour, as well, and having to eyeball, then arrange the various elements of the UI by "freehand", drove me nuts. I literally did not want to play the game, knowing that, before I could do anything with my character, I'd have to spend at least an hour trying, then failing, to get my layout as close to symmetrically perfect as possible -- and there's just too much "stuff" floating around the screen to even make that remotely feasible.
At any rate, I agree that it would be nice if BioWare could introduce their own official design tool into Interface Editor in the near future but, well, it's been three years since this idea was suggested. I don't hold much hope.
Still, very odd that, after all this time, we both come to the same spot to post the same information. Hopefully, this double endorsement of the ClovisGrid helps a few folks with the same nagging issue.