Having used DVD Decrypter in the past I can safely say there is nothing wrong with it. It does the job of decrypting and dumping the files/image to disk. What you should now do though is grab some software like CloneDVD. You can point it to the directory you saved to and you can choose which audio streams and chapters etc that you want. Then you can click to proceed, let it process and burn the result to DVD.
That would be 'a' method. You could also use something like AnyDVD in-place of DVD Decrypter, but I believe you'd still have the extra step of removing the french language. As for the one you already made though, are you sure you can't change the audio track with an appropriate control? Usually there is such a button on a DVD remote (or in PC DVD-playback software). It sounds like French is the primary language here, and it is simply playing that by default. One bit of software I would avoid though which you have used is Nero Vision. Just from experience. Nero should have sticked with it's burning engine and not ventured into multimedia stuff, imo
~Psych