Pirkei Avot 1:17 suggests that silence is the best thing for the body, and that one who talks excessively, brings about sin.
View Rav Bartenura's comment as well as his reference to Mishlei 30:6. In explaining the 2nd concept that talking too much brings sin, he mentions going beyond what G-d has directed you (as in the case of Chava). I think one can make a kal vachomer that if one adds more than what G-d himself has told you, and that brings about sin, one can generalize that any form of excessive unnecessary speech can bring about sin, as well. Banter is a form of idle speech (I'm not even addressing the possible prohibitions of causing someone unnecessary suffering by teasing him).
As for nicknames (I don't see the relevance of this to banter), we do see various "pseudonyms" given to rabbis in the Talmud as well as more contemporary rabbis. These names are useful. Giving someone a name just for fun, seems like a form of "oppression". Even if the other person doesn't mind, if there is no useful purpose for doing so, why do this?
From personal experience as well as my observing others, many nicknames are established in elementary school, and most of the victims don't like it. Frequently, it's a form of bullying, but the young child can't fight back. The nickname sticks around for years, and, eventually, the victim tolerates it, but it doesn't mean that s/he likes it.
On the other hand, "professional" nicknames and "shorties" (E.g. "Jake" for "Jackie") may be helpful. In the end, before assigning a nickname, one should ask if the person is OK with it.