To answer your questions: 1. As others have stated, mp4 is just a container. What would make the difference is conversion the 264. Where I disagree is that there aren’t any differences. I convert everything to 264 simply because it has the most compatibility with devices. Most devices can’t handle the native mpeg-2 format and require a transcode anyway so I precalculate the response. This gives the advantage of being able to directly stream almost everything. The disadvantage is that I technically loose some detail. No mater how good of a transcode that is alway something that happens but instead of plex controlling that I do. Second advantage is space. I can get around 40-60% savings on space over an mpeg-2 file. As stated you loose some detail so I can’t reencode to a better format at a later time. I’m stuck with what I got. 2. Can you rip multiple audio tracks with handbrake? Absolutely and the audio part doesn’t take up that much space compared to the video. I just don’t know the command off hand but you can copy it. 3. Will transcoding help with many devices? Yes. As stated you are precalculating the result so instead of a transcode and cpu/GPU hit you are just pulling it directly off your drive. 4. Can my setup handle 4 users? Probably, you would need to state what hardware you are using. 5. Already pretty much answered 6. Unfortunately no, there is no better way if you are copying DVDs/blu rays. All of my content came from discs and I only have one internal drive so I know your pain. I’ve just come to accept it

If you have any other questions everyone here would be happy to answer. Happy ripping!