That's a fine explanation, but the fact that his lightsaber changes color is a gaffe, it's supposed to be blue always, until he loses it on cloud city and builds a new one that's green. In the original movie it was blue/white, it only turned green in the special edition and then in the 2004 edition they fixed it in places but generally screwed up all the saber colors (Vader's appears violent/pink or even orange in a few scenes). This is not normal lightsaber behavior of course, because it didn't happen in previous versions of ESB, ROTJ, or the prequels.
The "final 3 episodes" won't be made, and they don't exist really, except in people's fruitful imaginations. The series ends with ROTJ (Episodes 1-6). Ysalamiri were made up for the EU (Heir to the Empire) and they're supposed to come from some remote planet, so they're a "secret."
It's because it wasn't Lucas' idea but something Tim Zahn came up with.