DVD Ripper DVD to .mkv Newb Questions

[Jarut]

I am new to DVDFab and am hoping everyone could help me get a grasp on ripping. I am looking for the best format to rip a dvd to and I think I am settled on mkv. I want to keep everything as close to the original movie quality as I possibly can. I am using DVDFab 9.0.2.7 and have a few questions:
1. The options DVDFab gives are mkv.h264.aac / mkv.h264.ac3 / mkv.h264.audiocopy / and mkv.passthrough. Is audiocopy and exact duplicate of the audio on the disc? When do you want to use .aac or .ac3?

2. Are you losing video quality by using mkv.h264 instead of using mkv.passthrough?

3. What should I set the Bits/Pixel to? From reading in here i saw that between .2 and .3 is good, but if I don't care about file size, should I just take it up to the max of .5 or is there no benefit in that?

[90312]

If file size is not a concern for you use mkv.passthrough the file will look and sound like the DVD.

[GregiBoy]

1. Audio passthrough is an exact copy of the audio track you select. AAC is used by iDevices and AC3 is Dolby digital for when you need to convert to DD. eg Your device will not play DTS.
2. Yes but in most cases it is unoticeable. Do some tests.
3. Try 2.5 and test thatit is acceptable to you (On your target device)

[Jarut]

Thanks guys, I appreciate the help. Last question, under Video there is a check box for deinterlacing. What is this?