Hey, making bows isn't a walk in the park... and there are a lot of good things about this bow, so don't beat yourself up.
I'd remove wood (SLOWLY) in the outer 2/3 of the limbs to get them bending more evenly. By the time they are, your bow will probably have dropped at least 10#, maybe more.
I wouldn't worry about "tapering the edges," other than making sure they are rounded, until you reduce the outter limb thickness.
Next time, when you are tillering, I would suggest that you don't bend the bow any farther when you notice uneven stress across the limbs, and that you definitely don't shoot the bow until you think the tiller is perfect as can you can make it.
Keep plugging away, you obviously have some good wood working skills, and by making more bows you'll improve quickly as a bowyer.
gabe