Ken,
I too was thouroughly confused when I first started. I know a bit about web design and code, but JSON was unfamiliar to me. I seemed way in over my head. However, I disagree with part of your sentiments, as just "replacing links" was really all I was looking for. I don't find that actual "coding", but all I was asking for was a sample template.
What's not mentioned in the tutorial is that all you need to do is copy the mumbo jumbo text/code from their sample feed:
https://api.myjson.com/bins/4tu28 and paste it into a JSON validator like here:
http://jsonlint.com/ and it nicely formats your code for you. All you then need to do is replace the names, descriptions, IDs, and mostly the video link URL. Just getting a URL should be pretty easy, I can't see how Roku could find it video any other method.
After all, let's not make it too simple. Gotta hope Roku can seperate the wheat from the chaff, otherwise it'll turn into YT.