Click on the "Q" in your aquarium if it is lit up and that guy will give you the quest. It's to teach you how to use your aquarium. If you cannot, then you've already done the quest.
Not quite sure what you mean by the second part, but if you post many times in a row very quickly, eventually the system will warn you to slow down and force a waiting period.
he's asking about captchas
Also what is with entering out text for some posts is it random or does it happen if you post too fast.
it is called a "captcha". basically it is a code to enter to prove you are a human being and not a bot. they pop up every here or there while posting, and it comes up every time you post a comment on a profile that belongs to someone who is not on your friends list.