Ok so far there is no way to play retail games that have been ripped except for the local devs using a dev console but it was only 1 game so far I believe they have been able to do.
Now your questions about putting movies on a dl dvd you can if you encode it onto a dvd (pretty much the same process you use to make a dvd that will play on dvd players) but if your ripping blu-rays then quality probably will be sacrificed.
If your thinking of burning the files directly to a dl dvd and have it burn as a data dvd with the movie file on it I think you may be able play it on the ps3. I may be wrong but I have not heard of anyone being able to do this. I suggest if you try doing this you must be able to encode the video files into a format the ps3 must be able to understand.
To test something like this I suggest getting a small video clip and test encode it to find the settings that can work for you. Then if you have one use a small jump drive to test the video in the ps3 os and if that works trying burning it to a cd and see if it mounts and shows the file. If it doesn't then I wouldn't but you can also try burning it to a regular sl dvd and see if the video file shows up.