Is the prayer of one who was ritually impure (janābah) valid if he was unaware of it, and is ritual bathing (ghusl) valid using a shower if the penis is touched during it?

What you did by performing ghusl (ritual bath) and repeating the prayer is correct. Prayer performed without tahara (purity) is not valid, even if done out of ignorance. Lack of khushu' (devotion/humility) does not affect the validity of the prayer; rather, it is one of its sunan (recommended acts). Performing ghusl under a shower is sufficient if the water reaches all parts of the body. Touching the penis during ghusl does not necessitate repeating the ghusl, but it does require repeating wudu' (ablution) if it occurs after washing the wudu' organs.