Sure I could use the MzScheme for this but I would do it in a "non-standard" way, e.g. it would be my personal hack. But right now, I would jump into programming a web application in Arc if I had an easy (and "official") way to interface SQLite3...
Arc really needs a FFI. This would make possible using graphical libraries such as GTK+. I know Arc is web-oriented, but for some type of applications a conventional GUI is simply better.