Do Not Do the Race Material
When you're going to do race material, remember the first rule of doing race material: don't plan on having a job when you hit publish. Oh, and kicking down and making fun of people is automatically going to get you fired no matter how "funny" you think you're being. Nobody laughs at this stuff anymore except racists and buffoons. Let me explain this to you succinctly: don't do the race stuff. It's that simple.
You may want to take offense and note that the only people you can make fun of are overweight poor white people, and that's okay. But, at the end of the day, you can't do the race stuff.
The great Phil Hendrie can do this stuff and thrive in the process. When some assclown working somewhere does it, he gets fired because he doesn't understand context and characterization.Oh, and what will get you fired ought to be at the forefront of your efforts to be funny. If you don't know what these things are, you're going to get fired.