Anyway it is a little painful to be going through the menus and configs that way. Its fine for starting something in theater view. I have a PC upstairs in a little office on the same network that I run itunes and sync my iphone. Any new music I get starts there. Can I install JRiver there - do the tweaking, create playlists, etc and send the changes to the other computer?
Absolutely. And, in fact, with the way you describe your setup, I'd strongly recommend you do it this way.
First, read up a bit about MC's Media Network feature:
http://wiki.jriver.com/index.php/Media_NetworkSynopsis:
MC can run either in standalone mode (as you've been using the trial) or in a client/server mode. The "server" in this case is not a different "edition" of MC, it is just the regular client, with the server stuff turned on. So, you can install MC on the office PC, and set it up as the server. This will work best if you have a network share that is mapped to both the client (the HTPC in your case) and the server using the same drive letter or UNC path, and media is stored on this share.
Then, the server "copy" of MC handles all "administrative" functions. You create and organize views from there, manage library structure, configure Theater View just how you want it, and everything else.
The client copy (the HTPC) connects to the server, and then acts like a pretty-much full fledged copy of MC, but it uses the Library served by the remote copy. Note that, if you have a laptop, this even works over the Internet (assuming you have a decent home Internet connection and open the appropriate port on your gateway). This is also the same system used by Gizmo, WebRemote, JRemote, and other "mobile" applications you can use with MC.
The client copies are able to play everything, and make changes to tags and playlists, but they aren't able to modify the structure of the Library (views, Theater View, etc) at all. In many cases, that's good, as it prevents "users" from messing up the defaults, and allows you to consolidate management to one machine.
When connected up this way, MC will actually even transcode and stream the files (that's how it works over the Internet). However, as I mentioned above, for use at home on a LAN you'll get better results, better quality, and higher performance if you map a drive on both machines with the same drive letter, and import the files there on the server. When a client copy of MC tries to use a file (for playback or whatever), it looks to see if it can find the same exact [Filename] locally, and if so, it uses that. If not, it asks for the server to stream it.
That makes it easy, and playback always works even if you can't figure out basic home networking, but it works better if you can figure out home networking and use a common share. If you prefer, and know how, you can also import files directly using UNC paths on the server (instead of looking at a drive letter), and then you don't have to map drive letters on any machines on the network.
For your last question, I find AnyDVD HD and MakeMKV to be the easiest, and most reliable way to rip BluRay (and DVD, frankly) at high quality. Disney movies can be... Challenging. I'd make sure you have the most recent version of AnyDVD HD (there might be a beta on their forum or something), and if that doesn't work, troll on their forums for tips. I'm sure others have encountered the problem.