Critical by RQS, new grower here

Hi mate, I think your plant is looking really healthy. The top of the leaf looks untouched by what is on the bottom so I deduce that its an effect of having the leaf so close to wet soil. I hope this helps, good luck and happy growing

It depends on the space left between the top of the plant, the level of the light and the ceiling. The plant will stretch during the first weeks of flowering, growing twice tall and will double in size. You must save some space and try to not finish with your buds to close from the heat of the light.