OK, I personally think that the remixes are out of Ayu's hands. She doesn't really control the aspects of the remixing, she pretty much just approves them. But all I have to say about that is of course they are going to sample from something...they are remixes after all.
Second, about Pride...that's not Ayu's song in the first place so technically, wouldn't it be Sweetbox that copied Crucified? haha
About tasking and taskinst...yea, I don't know. I think tasuku may have copied them, or maybe he actually came up with those beats himself. No one really knows for sure except tasuku.
As for Endless sorrow ~gone with the wind ver.~, I think that one is a stretch. I don't think it sounds anything like U2's Where the Streets Have No Name.
These are really good comparisons though. It actually makes me want to listen to some of those original songs now.