What you're missing in your GCT File is the File Patch Code. That's the code in your GCT File that allows for all those custom mods and such.
Here's a really basic GCT file for ya!If I remember correctly, RSBE01.gct files for both Riivolution and Gecko are identical; but the difference is that Riivolution runs music perfectly, and I think that Gecko doesn't do it properly.
You don't know what you're talking about. The only difference between the 2 is that Riivolution doesn't need the File Patch Code, for it already comes with one.