Nah, her E is OP (As it needs to be, seeing as she only has 3 skills) as is. I made an enemy ranked team surrender at 22 minutes last night because they had no idea how to deal with Karma top. Totally shut down Panth by shielding his spears and harassing him with non-physical damage. Kill him, so they send Akali top, who I kill by layering AoEs over her bubble. 10 kills, a Deathcap and a few 500 damage shields + absurdly huge AoE nuke, with an AoE %heal in there and they surrendered.
I only recently started playing Karma and I swear she is the best top in the game if you can pick an engage for jungle or support and don't need it top. With farm, she is the best team fight support in the game and fits into any team comp. Poke comp? Movespeed buff and huge range poke on her mantra-E if you use it on minions at max range and a heal. AoE teamfight comp? She has three AoE damage skills, though one of them is hard to connect with. Hero-Carry style comps? She has a massive shield and a movespeed buff that slows any enemies the line touches, and a heal of course.
The champion remakes are very hit-or-miss, and Karma doesn't need one. She is a terrible lane support compared to Lulu, who does pretty much everything Karma does without the lane pushing AoEs as her only harass and with more hard CC. What Karma does is wrecks face in a solo lane, as her abilities scale very well, and she has 6 skill ranks to crush in the level scaleing department.
Riot, if you want to make Karma better as a support without buffing her solo, don't be idiots and remake her. Make her tether like Wisp in dota where heals on herself effect her tether target. Which makes her tiny heal double proc on the tether target because it heals herself as well, and she can chug potions to help keep her carry in lane. BLAM. Suddenly she isn't lagging behind all the other supports because she has sustain. But it is on a significant cooldown due to Mantra charges and is incredibly mana-intensive so she can't hyper sustain like a Soraka.