1) its too late to get seed, you need to pollinate on like week 3-5 of flowering, your way past that. You don't get Feminized seed by stressing plants out, you get hermaphrodite plants that ruin crops.
2) No the plant will start to revert back to vegetative growth, giving the appearance of increased size, but just the leaves and stalk are bigger, the flowers are smaller. Counter productive. leave it at 12/12 for the best results.