Try this before you give up on it...
MetaX is great and I am one of those that swear by it. One thing that you will definitely want to make sure is that you go into the preferences and check the box that says "Enable support for large files". I figured this out when I first started using it a couple of years ago and then refreshed my memory the hard way when I installed this on a new Mac recently and forgot about this little detail leaving several movie encodes with audio when played through Apple TV but the video was just displayed as a black screen. The interesting thing is they played audio and video fine through iTunes so the lack of that preference only affected the playback of video through Apple TV.
Also, I obviously can't speak for Omne666's personal experience with tagging or using MetaX. However, after ripping 300+ movies with Handbrake and using MetaX to tag all of them, I have never run into an issue with the file name preventing me from tagging a movie or causing the file to be unreadable so I don't believe this is the issue. Maybe it's different with iFlicks as I have never used that application but it seems to make no difference with MetaX as long as OS X lets you name the file, it should work fine.
Other suggestions for tagging info and artwork...
Getvideoartwork.com &
Themoviedb.org for artwork
iTunes store,
Netflix or
Wikipedia for info (release dates, ratings, genres, long descriptions, actors, directors, producers & screenwriters)
If you can't find a particular movie or concert film to get a description off of from the previously mentioned sources you could also try
coverparadise.to or
Google image search to find scans of actual dvd/blu-ray slip covers.
Lastly, chapter names can obviously be found on the DVD you are ripping.