It can rip and burn CDs, convert between different audio formats.
In addition to convert CD to FLAC, the OS X CD to FLAC Converter can work an audio converter, video to audio converter, CD ripper, CD burning and audio editor. The CD to FLAC Converter for Mac – ImToo Audio Converter Pro for Mac can easily rip CD to FLAC format on Mac OS X. You can see if there are third party utilities such as Burn which will do it all in one step from FLAC files, otherwise you may need to convert to something iTunes will accept (I'd go for ALAC or AIFF over WAV) and then use iTunes to create a music CD, not a data CD. I'd normally recommend iTunes but it won't accept FLAC files. I suspect the methods you have been using are creating data CDs which are okay for computers but only supported by a few regular CD players. You may need to create an audio format CD which is the standard kind for regular CD players.
