I like your program. But.... I think that under GNU/Linux the program could benefit from using ALSA instead of OSS. Also. If jack could be implemented I think that a more professional audience would use it.
You can already use ALSA as output. If you compile mp3blaster with SDL support, you can have SDL choose the audio output device.
You can set an environment variable (IIRC, it's SDL_AUDIODEVICE) with a value indicating you want to use ALSA. I thought I put this in the FAQ, but apparently it's gone missing.