If I was charged at the border but then all charges were dropped and I never had a court date or case do I still need to fill out an I-192 form or should I be able to go across the border from Canada to the US without hassle?
Do I need an I-192
I wouldn't say "no hassle" as they are probably gonna dig for details, but since you weren't convicted of anything you should be fine.
And that goes for other recent posts I've read lately: charges don't mean squat. It's convictions that they are looking for. Despite what you may read about, being convicted involves going through due process and having representation in a court of competent jurisdiction.
Now having said that, if you haven't gone though the court process yet for outstanding charges it is at the discretion of the officer on duty or perhaps his or her supervisor as to whether to let you proceed or not.
Or else any joe blow could press charges against you and hold up your ability to travel.