I've been typing Mandarin with pinyin input for years and have never found it terribly difficult to learn. However, I am finding that when I need to use website and type Cantonese expressions, I find it burdensome to try to find the appropriate character in Mandarin pinyin, so I'm trying to learn the cangjie input instead.
I am currently looking at this website on how to learn and the diagrams and instructions are a bit confusing to me. For example, it looks like they are building characters from radicals here, but the construction seems odd:
Here it seems they are using logographemes instead of the actual radicals. The bottom diagram is even more confusing because its not immediately clear to me what 卜 is doing to create 辶. What is the proper way of typing the characters if the keys themselves are radicals?