I've had difficulty placing it properly, as well. Seems like it would almost be, counter-intuitively, better on a Renegade, since they're in Reaper's Touch range anyway. The Oppressor is farther from the fight. And, yes, you could put it in your Tab slot, but you get more out of almost any other spell you put there. That…
The recommended thing looks purely at Gear Score, not actual stats, so just ignore it. Power->Crit->Recovery is the core itemisation for the Renegade build, obviously. I'm not doing Renegade on my CW, though, so I've been building Power->Recovery instead. Gotta use those Encounters and Dailies as often as possible. :)
There are lots of good ones. The hard part is choosing which two to put in your build. Personally, I go primarily for icy control effects. So, Orb of Imposition and Chilling Presence for now (only level 28). One thing I've noticed is that I think OoI affects Chill duration. I used to see my Chill stacks fall off of targets…
Don't blame this on 4e. Neverwinter follows 4e very loosely. Mostly, it just copied names of things and invented totally new mechanics around those names.
MOBA games know the perils of allowing too much hard CC in a game. It's anti-fun. That's why they often introduce some kind of anti-CC stat or item. LoL has Tenacity and the Quicksilver Sash, DOTA has the BKB, etc. Even Lord of the Rings Online -- to use another MMO as an example -- introduced a PvP-only stat called…