The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at You Know, That Thing Where.
I'll be honest, I assumed Verbal Tic was just for one of two words, but the other examples fit.
I think Flexo would also fall under "Just Joking" Justification, in that he'll blatantly insult people to their face and then laugh and say he was just kidding. Unlike Bender, who just insults people to their face.
I didn't write any of that.
Seconding Verbal Tic overlapping with "Just Joking" Justification in Flexo's case. Verbal Tic does mention it can be a phrase (and I'd take that to also cover variations on a phrase) rather than just a single word or sound.
Flexo, from Futurama, has this thing where he says something, then immediately says "nah, I'm just kidding" and the opposite. It's not a Mad Libs Catchphrase since it doesn't change just one term, but the entire phrase, and it's not a Strange-Syntax Speaker since the grammar isn't wrong.
Plus, the joke is that Flexo speaks like that all the time, which makes him sort of a shallow character.