1) I know I could have (easily) tiled the stage to make it wider, but I actually intended to keep the stage this size. It was originally meant to serve as a stage for a full game project that O Illusionista was working on (though progress on the game seems to have come to a screeching halt), and those were the initial dimensions I was given if I ever decided I wanted to try my hand at creating stages for the game. I may or may not make them bigger at some point, but I figured I'd give it a shot anyway. "Fun" is really a matter of personal taste anyway. I, myself, enjoy the stage for what it is.
2) Honestly, I didn't even notice this. Fixed. And thanks.
3) The location for the music in the stage's DEF file is one that works fine for me, given how I have my folders arranged. You can place the BGM anywhere you'd like (according to your own file arrangement), open the stage's DEF, and type the path out. This sounds like nothing more than nit-pick (and comes off a tad rude, though I won't make a big deal of it).
4) I'm just getting into making stages, and still have much to learn. That being said, I'm not exactly familiar with "Sin.Y" just yet. I made it the way it is now because it accomplishes the same thing I intended to do in the first place in a way that I felt was the most simple (to me, anyway), but as I continue learning and experiment a bit here and there, I'll eventually make use of the other BG controllers. As soon as I figure it out, I'll be sure to update the stage with it.
5) Tile spacing may "require" 2 values, but the way I have it now seems to be working fine so far too.
6) I've never really noticed anything "wrong" with the deltas per se. Care to elaborate on that?
Though I got a rude vibe from your criticism, I'll keep at it and try to learn from it. Thanks.