I just connected my wiring to the terminal posts: each connection is a possible failure point and can add resistance. I'm just a nOOb at
this stuff, but I've been doing cars, bikes and computers (separately!) for years.
As for cases- I did put my psu in a project case from Radio Shack. Not a major process, and it does allow me to have a dedicated fan forcing airflow over the board while reducing the chance of something shorting out.
Of course, my whole computer is in... well, more than a single case.