First off, I love the guide
Second, Shaclad I read your post and I have to disagree.
Assuming a lvl 50 Sith Assassin got 10.000 health, the 2 points in "Shroud of Darkness" you'd gain from removing the points in "Swelling Shadows" would equal to 200 health. That's not a lot of health gained, and I believe that (when doing the math) it's a bad tradeoff. Not sure about it though, just a hunch!
"Force Speed" is on a 20 sec CD talented, the "Unbreakable Will" is on a 2 min CD, so the "Disjunction" talent aren't wasted. Furthermore, the "Force Shroud" aren't limited to stealth only as far as I could see on [Torhead, it just doesn't break stealth.
You also mention removing the points from "Harnessed Darkness", a mistake in my mind. The "Force Lightning" ticks 3 times, and with the talent it can't be interrupted and heals for 3% for each tick, that's a 9% heal costing 30 force.
Lastly, "Spike" is an ability with a 2 seconds duration, and a 30 seconds CD, so while the 9% increased damage from "Nerve Wracking" is amazing, then keep in mind that your teammates in the flashpoints/operations can only get 1 ability off in that period (or, with amazing timing, 2).