* What video formats are compatible with LMCE? I have a few .avi files that seem to work, but a movie as .ogv isn't recognized.
LMCE can play lots of different media. We currently use libxine2 1.2.6 and can playback anything that it supports. I have never personally heard of the .ogv file format.
* Once I'm playing a video, how do I stop it? I cannot seem to find any way to stop the video from playing - it just has to go all the way through or I have to reboot the system.
Press F7 (I think it is) on the system that is playing and it will bring up an orbiter onscreen that you can use to control the system. The other option is to choose the room that is playing from another MD.
* Can I rip a DVD from within a media director? I tried to insert a disc, but it just started playing and then I was stuck without a way to stop it (see two questions up).
Discs will auto-start playback. You can then stop it and choose to rip it using the Manage Drives scenario in the media section on an Orbiter.
* I did quite a bit of work to get shared folders operating in VirtualBox. It seems the Guest Additions that Kubuntu 12.04 wants to use is the wrong one, so after some gymnastics I have a nice set of links to my guest system that auto-mount. In the process of working at the terminal, I have the strong urge to update things, but the strong urge not to. Any problem with updating kernels, applications, etc? Or, are these better left as is?
LMCE *may* undo things that you do. The ultimate purpose is a black box system that requires little to no user hacking... In reality we're a ways away from that goal. We already use the latest LTS supported kernel from ubuntu (3.13.xx) right now. Changing the kernel will likely break X as ubuntu builds it as an LTS update against the latest LTS kernel and the modules/libraries all have to match.
Other than that you can usually add things on. Not sure what you mean by updating. Feel free to apt-get update && apt-get dist-upgrade
* In setting up a Media Director, I don't see an option to simply install a Media Director OS. The install seems only to allow a headless core or a hybrid system. If I install another hybrid, will I have issues with my existing core? I cannot find a netboot option on my chosen MD system, unfortunately.
You cannot run a MD without a Core. Hence to install option is a hybrid (Core/MD) or headless core. You cannot install additional Core or hybrid systems, you must PXE boot to create MDs.
I hope that helps a little.