Whenever leaf tissue disappears, something is eating it. Your challenge is to find that particular something.

Many a critter "cant be found" but that's usually because it's on the underside of the leaf or because it feeds at night.

So, your task is diligent inspections at various hours. When you find the critter(s) you probably can dispatch it(them) on sight rather than apply any sort of product.

Very effective techniques are squishing, snipping in half, or flicking into soapy water. Your need to chose what will be appropriate when the time comes.

Leaf curl is most often the result of turgidity, water pressure in the leaf, although there are some insects that do curl leaves. Either the plants have too much water available or too little, since both can cause leaf curl.
As Jean wrote the holes in the leaves most likely are caused by an insect.
The other problems may be related to nutrient availability and too little or too much water in the soil can cause that too.