Not sure why an elite mob has people running scared..
Obviously gameplay is very different as a Sage, so I can't comment too much on that.
Interrupt everything you can is the best way of cutting Sith damage. As mentioned also by someone else, CC the toughest mob, cut down the lesser guys first.
Shadow Tank here with Tharan healing me, havent had a single issue with any class quest. Always been 2-3 levels above the mobs and keep gear on both myself and companion upto date.