[KyleGoetz]

Thanks, Nagoyankee. In para. 2, I was really trying to draw some sort of similarity between the inclusion/exclusion of は as "formality" in the same way you can informally say 食べたことない in speech but would say 食べたことガない to be "correct."

I didn't really mean it in a する／します way. But point taken.

And thanks for clearing up the point for me on what the は actually adds to the structure. Occasionally I find things that I don't quite get and need someone to ask. As I'm busy with grad school, I don't have a chance to go out and find Japanese people to ask anymore.