Sorry, as described on the product page, DRMed music isn't supported. I don't have any tools that could decrypt them and even if I could, it's illegal under US law for me to provide an application that converts them. Apple (or whomever's DRM is protecting the music) would likely sue me.

Can you support Sony MSV, Olympus DSS or RCA VOC format?

I would like to be these are proprietary formats with unreleased specifications. Please contact the respective companies and ask that they release a specification or OSX developer library.

Can SoundConverter convert tags?

Yes, tag conversions are supported for the following formats: ape, mpc, mpeg, mp3, ogg, vorbis, flac, mp2, mp4, m4a, m4v, speex, tta, and wv.