Stone circle prevents someone from fleeing particularly unfavorable situations, such as being attacked simultaneously by several hostiles. Possible actions include: 1) hiding, which is easily countered, 2) teleporting, which beyond a 1v1, it is rather difficult to do without being fizzled (barring being in protection, even then LOS for teleport can be tricky), 3) coordinate a dispel field with someone not being blasted.
I also have commented on grasping roots in past for being a non-resistible paralyzing spell. Resisting spells reduces paralyze's duration; something similar might be considered for players who are rooted.
The biggest problem is that the cleric and druid book were never made for pvp, they are pvm spells, so fixing them for pvp will make them useless for pvm.
This is the heart of the matter.