You didn't start a ruckus. We're perfectly capable of starting one all by ourselves. ROFLOL!
What are you confused about specifically? The biting during play? This is normal puppy behavior. Puppies are dogs. That's how they play, teethe, explore, feel things, interact. They know how to be one thing......dogs. They don't speak our language and we don't speak theirs...at least not very well. But scientific learning laws will work to teach, along with the maturing process of your pup as maturity develops. Growing into an adult doesn't happen overnight. This and all growing up takes time, experiences, education and just getting older. Its just like with people babies. They don't turn into well mannered, educated adults until they are more mature.
Its not too complicated and you don't have to worry about hurting or causing fear or pain, undue confusion at all in your pup.
Simply, remove the payoff from the dog when engaged in an undesireable behavior. In the case of nipping while playing, what is the payoff? Your continued playing, attention and presence. Remove it all at once when the pup bites and it comes even close to hurting. Get up, leave for a couple of minutes. Be sure puppy has a suitable chew toy that will feel good on the gums. Try again in a few minutes. If puppy is gentle with your skin and mouths ever so gently, stay there with the pup. Let her know that this is a nice way to mouth. This way puppy learns her own strength and later on if anything causes her to bite, she will be apt to lessen the pressure of the bite.
Once she gets it (after several weeks and lots of reinforcement and consistancy for the right way)....to mouth gently and that the slightest pressure with her teeth causes all the fun to end and causes you to leave, she'll choose the better way to mouth.
Then you can start teaching her that the gentle mouthing game is only allowed upon invitation. At that time, you can again end the fun when she instigates the game and you show her that only when you instigate the game is it allowed. You can then add a cue word if you want when its time to stop the game, such as "enough." As soon as she stops mouthing and keeps her mouth to herself, say, "enough." And praise. She will associate that word with the stopping of the mouthing. Don't use the cue word while she's mouthing at first or she'll learn that the cue word means to mouth. Distract her if you need to and only use the cue word when she stops. Later, once you can tell that she's made the connection between the cue word and the stopping, you can try it ahead of time and see if she stops. If she doesn't, make sure you do something to make her stop. Take your hand away, end the playtime for a few seconds. If this happens, it means she hasn't made the connection yet between stopping and "enough." Go back to using the cue word with the stopping, not before for a while.
Some people prefer no biting, mouthing at all. But personally, like with my Doberman, I taught him gentle mouthing upon invitation. He knows the amount of pressure he can exert and knows how to regulate it to a T. He knows what is acceptable and what is not.
Puppies learn some of this from their littermates. But its like they have to learn it all over again with their humans. They don't understand how fragile our skin is. Its a rather complex concept for a dog to go through that kind of reasoning, so harsh punishment, pain, causing fear, scolding is IMO not fair and doesn't teach the dog very well what it is you do want from him. But it can teach the dog that you do scary things and aren't to be trusted. Of course, these things come in varying degrees. I prefer the method I described because it teaches the pup what you DO want and the only awful thing that happens is that the fun stops upon an incorrect response and upon a correct response, praise, treats, continued interaction reinforces that correct response. Reinforcement is what causes behavior to be repeated. (law)
I hope I didn't confuse you even more.