I always went for the soft cap when it came to defense ... 45%; anything over is wasteful. Easy to soft cap most Corruptor builds while not sacrificing anything
55% is overkill and leaves you with only 1 single target attack that's slotted for anything really. No need for two holds...again aside from the set bonuses which ya don't need. Wouldn't slot brawl..nor take spring attack (melee is not your friend). You didn't slot Rain of Fire... and you under-slotted Fire Ball.
Tar Patch + Fire Ball + Rain of Fire + Fire Ball= win.