There are no pure editing programs for dvd video that also include a decryption capability. You'll have to put up with at least two programs.
The two best programs for decryption of commercial dvds are DVDFab and AnyDVD. Neither are free, though there is a free section within DVDFab that will decrypt and rip the movies to the hard drive even after the trial for the main part of the program expires. It is called DVDFab HD Decrypter. The only caveat is that the free section will lag behind the commercial one in decryption abilities by 8 weeks or so.
How much editing do you intend? If you just want to remove certain soundtracks, or just get the main movie, there are ways to do that with DVDFab, or with a free program called DVDShrink in combination with AnyDVD.
If you want to make cuts and save sections that can be done with DVDShrink also. Look through the many guides for using it online, at www.mrbass.org or www.dvdshrink.info You'll need either AnyDVD or DVDFab Passkey working in the background to break encryption on many newer dvds if using Shrink though, since it has not been updated to deal with newer protection schemes in about 6 yrs.
If you want even more editing capabilities, such as transitions or mixing and rebuilding dvd video, you'll need a dedicated editing program like Womble Mpeg Video Wizard DVD or VideoRedo TV Suite.