So, I finally got something to go well on my server – I successfully got MiniDLNA set up as a media server on my system. After loading some videos, pics and tunes onto the server as test material, I was able to stream it to my LG Smart TV. (Through LAN cable) I then was able to move the mount point to my 3TB drive.
The biggest problem I had was getting my Buffalo WZR-HP-301NH wireless router to stop assigning IP addresses with a different subnet address to my wired and wireless devices downstairs. (Unless you're on the same subnet – your devices won't pick up the media server.)
The Buffalo WZR-HP-301NH is a Japanese only version of the 300NH. Basically, I just had to swap the cable from the main router from the WAN port into one of the LAN ports, then I changed the router switch from on to auto and tried to connect to the Net (on my iPhone.) I was instructed (in Japanese) to put the main cable back into the WAN port, after which the router detected the main NTT router and allowed it to assign IP addresses to the wireless devices. I've checked all devices running off the Buffalo router, and they all have successfully acquired IP addresses from the NTT router and are able to stream from the MiniDLNA server.
The PS3, iPhone (through iMedia), Windows 7, and Windows Vista are all able to stream media. However, only my LG Smart TV is able to play MKV files. This has been discussed aplenty around the Net, so I won't go into detail here. It's great finally being able to watch some movies on the big TV downstairs without burning DVDs and even better, streaming to the TV in the bedroom, so I can watch a little Louie C.K. before passing out.
One point: Since I interact with my server primarily through Webmin, I have installed the Webmin module for minidlna. While this is very handy, simply using the rescan button does NOT automatically scan and restart the media server. I also have to log in to the server and enter the "sudo minidlna" command. This gets the media server back up in the network with all the newly scanned changes applied.