Nikos: I can only answer the first of your questions. Based on my experience, peppers very definitely prefer to be shaded from the hot, midday sun. I discovered this by chance. Those peppers which, for lack of space, I planted in part shade did better. Much better. Now, I try to site my peppers so they receive at least a couple hours of filtered shade. Not deep shade, but nicely filtered through the leaves. I'd love to hear the experience of others with shade/no-shade. Txs! Robert.