mp3 has similar compression rates to wma but lacks any sort of annoying security. WMP is big on needing xtra codecs to play AV. See the following links for comparisons (too big to include here): http://www.insearchoftruth.org/audio...ke/encode.html
http://www.updated.com/browse/index....en+MP3+And+Wma

No, mp3's can be burnt as either an mp3 disk (basically a data disk) or burnt as a full audio cd. Generally the burner software will convert the mp3 to the full size of audio tunes (wav & aiff are direct formats that save in full audio quality.) Just choose audio cd in the burner app & drop your mp3's in there.

mp3's & wma are generally compressed in size using 'lossy' techniques (throws away info thru a no. of methods; eg: combining the 2 L&R channels at times when the difference is minimal.) Hope this answers your queries.