CV : I think MakeMKV will be your friend there (http://makemkv.com/
Blu-Rays have several accepted codecs for both Video and Audio.
Video is one of MPG2,H264,MP4 or VC1.
Audio is one of AC3,DTS or LPCM
In any combination, MakeMKV will extract the tracks from the BluRay and store them into an MKV file without tampering with the original content (it will just decrypt the AACS stuff on the BluRay if there is any).
Once you've got the MKV file(s), you can pretty much cut/chop/join/reencode/compress any which way (you'll probably want to use VirtualDub at that point).
"Backing Up" media you own is perfectly legal :-)
Let me know if you need any help with that.
Murph : If you use VLC version 2.x+ and add libaacs (google is your friend there), you'll be able to play any Blu Ray natively anywhere and on any ouput.
In fact, CV, you'll probably want to use VLC to playback your MKV files as you can create playlists with them.