I considered this but then went the other way - a \ before anything other than a \, newline or comma is treated as an error. This leaves room for adding featur

I considered this but then went the other way - a \ before anything other than a \, newline or comma is treated as an error. This leaves room for adding features, e.g. \N to signify a SQL NULL. Regarding quoting and escaping, there are two options that make sense to me - either use quoting, in which case quotes are self-escaped and that's that; or use escaping, in which case quotes aren't necessary at all.