EDIT: Believe me, I'd love to do it, but like I was saying, if it's up to me, I'd want the blood, crosses, and nude statues restored- not to mention a way to add back in the dripping blood at the title screen. That would go beyond the scope of just modifying the palette, which is why it seems like a simple translation of the Japanese intro would achieve this goal with less effort. If you could help me in inserting the english intro into the Japanese version, then I'm all ears, but keep in mind I have 0 romhacking experience!
P.S thanks for the update; it looks amazing!
Actually I think trying to hack the introduction text for the Japanese game would be harder.
Remember that you also have to translate the title screen along with the text, and believe me when I say it, if hacking EarthBound has teached me something, is that hacking SNES title screens is a pain in the ass.
Hacking the game shouldn't be THAT hard, although I've read that hacking Konami specific games is quite difficult, and proof of that is that there is no hack of SCV4 that I know of.
I did screw around with the game a little bit, and it seems that the graphics are all compressed.
So for the graphics we have 3 options:
1) Use the SCV4 Decompressor which I have no idea how it works. http://www.romhacking.net/documents/416/
2) Use the Konami compressor/decompressor. This seems like the best choice so far:http://www.romhacking.net/utilities/1101/http://magicteam.net/forum/index.php?topic=430.0http://romhacking.ru/news/konami_snes_compressor_decompressor_win/2014-11-12-2846
(For the last two pages, use the "Translate page" option to be able to somewhat read them).
3) Use a debugger like Snes9x or bizHawk to pin point the location of the graphics and, once the location is found, figure out a way to decompress them, edit them, and compress them back into the game.
The palette change for the goop is the easiest to do. xD