> Mandatory password change intervals.

Hasn't been best practice for a decade.

> Insane rules for constructing passwords.

There needs to be a minimum standard. Generally length is enough, but the special character type stuff is annoying.

> Completely undocumented password requirements that you just have to figure out by trial and error.

I haven't come across this.

> Complicated error messages full of security jargon. "Secret Questions" that you can't remember the answers to.

That's a you problem.

Y'all complain about password breaches but want to use Mypassword69! for everything. Pick a lane.