No, a pack of fems will not give you plants that are all the same pheno (even s1s produce a variety), and no, if the plants came from a reg seed, it doesn't mean they will be better than the feminized counterpart. The phenos will be different though, considering the male pollen and feminized pollen will pass on different traits due to the fact that it came from two different plants.
This is also false. It's all in the genetics that are being used. If the genetics are prone to turning hermaphrodite, buying regular seeds won't avoid it. A lot of females from seed, regardless of the genetics, will throw out a few male flowers (on only the bottom of the plant) early in it's life. It's normal, doesn't mean it's garbage, and will likely grow out of it after taking clones for a couple cycles. The pollen is safe to play with from those temporary herms as well and will likely produce stable offspring.
If the female throws male flowers in large numbers and they spread toward the middle and top half of the plant, it's garbage and will not grow out of it. The pollen is worthless as well.