I have recently lost a lot of weight and seem to have extra skin with some fat covering my lower abs. Not necessarily . . . For some, the skin's elasticity will change over time back to its normal state. But admittedly, others' will never change. You may want to give it a couple months for improvement, just to make sure it isn't a temporary state for your skin.
Whey protein is definitely the best type of protein for building muscle.
There is no right or wrong way to take it. In other words, you can supplement with protein at any time of day. The body will only utilize what it needs. Excess just becomes waste. On the other hand, you don't want to overdo it because the kidneys will be forced to work overtime.