I have no idea how you can improve those Ys arrangements. Actually, to be 100%, absolutely honest, while the Ys VI intro music remix WAS good and original, it wasn't in the same level of awesomeness as your other Ys tracks, I found. There was... SOMETHING it was, compared to the others, lacking? But it was still awesome.
Honestly, since those were my earlier tracks, I'm picking up on a lot of errors and instrument issues. I was new to the music software and didn't really switch instruments around much, so they all kinda sound the same, with occasional garbles of dissonance.
I think the Ys Redux's main mission would be to not only clean up those errors, but provide more cleaner instrumentation as well as add some of that "oomph" some songs need. (I'm looking at you, Protectors and Holders of Power...)