What other software do you use to add ID3v2 tags?
Well one which I bet a lot of other people use is iTunes. From the looks of it that'll only use Unicode for the tags if there's a character which can't be represented by the ISO-8859-1 encoding, which is why I never have any trouble.
As far as other programs I've used, there's about a dozen different audio players, tag cataloguing apps, and custom scripts using open libraries/modules I've used. All of them have used ISO-8859-1 tags aswell by default. I guess this will become more and more of a problem though as Unicode continues to get adopted by more and more programs (as it should).
The ID3v2 tags must always be before the audio data, it doesn't matter what program you use.