Oldfan said:
I do agree that the warning is pretty much useless. ...

I still disagree. FF, I suggest continuing to use the warning. Fair use laws are fairly nebulous. But one of the four things that courts look at when deciding is it's use for commercial gain. If you place the warning, you'll be less likely a target than fan editors who don't. It's not any sort of a guarantee against prosecution. But it might be one step in your defense's job of swaying a jury. And if lawsuits are ever brought against fan editors, I think it's safe to say they will target the biggest offenders first and those actually doing it for profit. Having a warning in the front will at least support your argument that you're not doing this for any gain. Actually, I'd suggest a disclaimer saying that you did this only for educational purposes (your own), which is another factor that the courts decided is allowed in fair use.

Like I said, it's not a get out of jail free card. It may not help you at all. But it could be a factor that helps your defense, if it ever comes to that. And even if some viewers find it annoying, it's really only a couple seconds of their time. No real harm in keeping it in.

Just my 2 cents.