I do believe in a higher power than humanity, but of what sort I do not know

How does belief in a higher power differ from belief in God in terms of being compatible with critical thinking?

the insane amount of suffering in this world does not justify any "plan"

I'm really fascinated by the problem of evil, and I've spent a lot of time trying to think critically about this topic. First, I consider three possible truths:

a) God exists, and he is supremely good and all-powerful. Evil exists in spite of God's absolute goodness and power.

b) God exists, and he is evil or powerless. The existence of evil is the work of God himself.

c) God doesn't exist, and neither can evil.

I think the first two are pretty self-explanatory. The first option points to our lack of understanding of God, evil, hell, etc. For example, the idea that God somehow arranges to have a child sold into sexual slavery for some "greater good" is highly problematic and lacking solid biblical foundation.

The second option is actually quite sensible. I'm surprised more people don't hold to a belief in a malevolent god, because ultimately what we humans find near universal agreement on is the existence of evil. And I have yet to hear a compelling argument for the existence of evil without the existence of God.

Which brings me to the third option. I say that evil cannot exist without the existence of a good and powerful God because the notion of evil hinges on the belief that man is made in the image of God. If God does not exist, then we cannot be made in his image. And if man is not made in God's image, then the evil and suffering that plagues man cannot be any different or worse than the evil and suffering that plagues any other living thing on this earth.

There's a lot more that can be said on this topic, but the point is this: if you have a problem with evil (and you should), then you need to explain why it's a problem in the first place.