Cool, found this guide which includes instructions to install/configure Plex and how to use it with a ChromeCast.
http://www.expertreviews.co.uk/tvs-entertainment/media-streamers/1400825/how-to-use-plex-with-chromecast-ios-android-apple-tv-nas
I still need an Android device to start "casting" to the ChromeCast. Guess I'll have to use my wife's phone until I get a new tablet.
Also it looks like Plex integrates subtitles (configured properly it will go and fetch the subtitles to match your video). Not sure if this part works with ChromeCast, though. Couple years ago when I was first starting out with ChromeCast (and with DLNA on my smart tv) I had some issues. Hopefully things have changed for the better, recently.
OK, so step 1, I have to install a bittorrent client on my home PC and download some stuff. Step 2 is install Plex and then configure it (apparently I have to be careful about separating the movies from tv shows on disk, as well as put everything in their own subfolders (a subfolder for each movie/tv show, a sub-subfolder for every season, and again for every episode).
OK, this will probably take me to the end of the playoffs
Certainly easier to just pay the man the extra $14 per month.