Pseudonyms aren't a silver bullet.

If you want a quick, casual conversation, I don't see why pseudonyms wouldn't be sufficient. You can also use random names if you're asking something really sensitive, which you would want to do in any case because it's a public space. For more in depth you can use your name if you want or a fixed pseudonym so you can recognize and be recognized.

There aren't many uncovered edge cases I can see.