Here's a workaround for the problem where you get rooted just before the MOB dies, which usually means you stand there twiddling your thumbs waiting for the root to wear off:

Workaround:

This only works if you have enough HP to spare. When the MOB has almost no HP left and roots you, hit "Q" to stop combat. The root will usually get cancelled as soon as the MOB hits you once or twice. You'll automatically hit back, which hopefully kills the MOB before it can root you again. This worked several times for me tonight.

Bug:

The only problem is that hitting "Q" several times near the end of a fight sometimes triggers the following bug (at least it does for me). Suddenly I can't use treatments, first aid, or loot the corpse until I zone out and then back in again. This cost me about 20k XP tonight, because another MOB rooted me while I was trying to run out of the mission area. It killed me. I could have survived the fight easily if I could have used my first aid kits, but the game wouldn't let me.