I've been teaching college level credit courses since 1999. I teach because it's what I am supposed to do - plain and simple. Over the years, I suspect I've learned as much, if not more than I've taught.
It's remarkable how many "stories" you hear and while it may seem simple at first, the task of having to filter these stories (from as classic as my dog peed on it to just about anything you can imagine) and act accordingly.
What I have learned to do over the years is become better versed on college policy and be as specific as possible about both the college policy and my class policy in the syllabus. It then comes down to enforcing the syllabus by holding everyone in the class equally accountable.
There have been many times where enforcing the policies in the syllabus help weed out the slackers effectively. Sadly, there are occasions where a student has every desire to work hard and be a good student but real difficulties in their personal life inevitably and inevitably, I need to withdraw a good student. I always hate when that happens but in our sadly litigious world, it just has to be that way.