Hi David,
Lilypond only cares about whitespace. Tbas are not integral to the syntax, as they are in some programming languages. Why don't you consider using Frescobaldi? Its a very capable and good lilypond environment. I cant see why, given that it exists, anybody would use a crude text editor. I can understand using emacs, however. Give it a go!
Andrew
I have been fiddling with textedit on Windows, and I have determined that when source files contain tabs, lilypond always calculates the "column" parameter assuming that tabs occupy 8 spaces. In my case I have my editor configured for 4 spaces, so the link always overshoots.