> The Canon Cat is a good text editor. That's about all it does.

Everything I've read suggested that Raskin intended it to be programmable from the beginning, using Forth. Other descriptions suggested that, while document oriented, it was not intended to be exclusively oriented towards word processing. At least not in the sense of the (dedicated) word processors of the day. That said, I'm not surprised that user interaction was keyboard based. The project had it's origins around 1978/79. It would be about 5 years until computers were sufficiently powerful to support a coherent GUI at a reasonable price.