Interesting read I appreciate the time you took to write this up. Food for thought definitely.

Welp having over a hundred music clips online i have an intro and a credits at the end but i see what you're saying
One question: are you talking about a video long watermark or interpersed watermarks?

Watermark the entire thing (one long watermark). YouTube provides tools to edit a video online and just about anyone with a computer has some video editing program. Watermarks and/or credits at the beginning or end of any piece can easily be chopped off.

To address my earlier points I just found a several of my videos hosted on overseas sites without any reference to their original source. If I hadn't watermarked them they would be orphaned pieces, no one could find me or my work and they could easily be copied, stolen, etc.

It's the digital age. If you can see it or hear it someone can steal it.