I think we should leave the leave problems. 🙂 But I agree with Ted. While it may be possible to read specific problems from leaf appearance, probably at best you can see a problem, but not know the cause. A certain leaf appearance might indicate a lack of nitrogen, but even if we are sure, the causes of that can be very different. It could mean the plant has been overwatered, underwatered, that its roots are diseased, that the pH of the soil is wrong, that the soil is too cold, on and on.