The early parts of the first Avatar series weren't very interesting, no.
And considering American animation is never actually animated in the US (because lel outsourcing to Asia), who knows what's anime and what's not. The wonderful thing that is Batman: The Animated Series, for example, had animation outsourced to studio Sunrise. Made in Japan. Is it anime?
I guess thoughts on this would vary from artist to artist. If it was me putting out art on the public domain, be it a song, a picture of Konata from Lucky Star eating a chocolate cornet wearing a school swimming costume or a video of me and some fellow football team members doing the Hare Hare Yukai I wouldn't mind what people did with it. In fact if somebody wanted to remix something I made it might even feel nice. Of course some will not but I would hope the higher percentage would agree with me, you're putting things on the internet after all
Out of interest what would your reaction be if you spotted somebody using one of your pictures as a set somewhere?
I'm not the old-timey, stubborn kind who wants to combat the sharing of my work. If the stuff I make can inspire others and give them ideas to continue upon, that's great. Work I do for money I don't generally put up online, anyway. The only thing I'm adamantly against is commercial use of things without my permission. But that's irrelevant.
From people using my things for purposes without monetary gain, all I can expect is for them to follow their morals and common sense. I'd rather not it be misrepresented/given a whole different meaning. But it's basically an honour system.
Which leaves giving credit. Something I expect of everyone to view as common courtesy. Of course I won't expect them to shove a big URL on their avatar. But a little title tag somewhere explaining where they got it from is appreciated. No matter what, it's usually fine if they don't start claiming credit where they shouldn't. Putting a photoshop filter over someone's drawing and saying "credit: me" isn't very nice at all, as you'd expect. It also annoys me whenever I see a photoset that says "credit: konachan/tumblr/google". It just shows a massive lack of effort to look things up (and it also makes you look like a massive tool).
But again, it's an honour system.
Regarding tags and signature banners and such in general, I don't mind them, because they don't hurt anyone.
Now, editing artwork might imply to some people that you don't consider it good enough as it is. That's something I want more people to consider. Adjusting colours and cropping to make it fit in your context is of course necessary in many sets. It's not done with any offense in mind, but once you start doing major changes for seemingly no reason, you start to wonder why exactly that was necessary.
Also, people who go out of their way to actively remove watermarks/signatures.