There was no benefit from converting mp3's to WAV's and then burning to CD. MP3's are lossy so by converting to WAV all you were doing was making the file sizes bigger.
The way forward .... I don't personally like itunes and avoid it.
Depending on your source of music (original CD or download) make sure you have mp3's at 320 bitrate and preferably constant not variable. Run them through MIK and then import into RB.