"Started to set them outside for a bit. "
How long is a bit and how often? It's been breezy to aweful windy across the nation lately.
Hardening off is a gradual process, protecting the seedlings less and less as you progress.
Are the leaves curled up or down? If curled up, were they exposed to gentle cool breezes or moderately warm breezes w/o protection? They may have become wind burned / shocked or transpired too much water.

If the leaves are curled downward, there is a potential they may have one of several leaf curl viruses, some of which are transmitted by whiteflies or aphids.

Paul B.

I am almost positive that too much fertilizer will cause the leaf edges to curl up. dont know what fertilizer causes it.

the solution is to wash out the soil with lost of rain water or other pure water. to dissolve the excess fertilizer and wash it out of the pot.

when the soil is wet the fert is at one point. as the soil drys out the fertilizer concentration rises.

I've noticed one of my plants has really curly top leaves, but mine were covered in webbing, like from a spider. I'm worried that it may be mites...though I suppose mites is probably better than a virus.

Zip

Odds are you have spider mites

ddw excess nitrigen can cause a leaf curl

if exposed to too much water....how to dry them ?

lack of mg causes leaf curl on chiles and many other plants.