Stress
You may get berated by angry players, but you'll eventually get used to it. You don't even really need to concern yourself with it because if anyone steps out of line, all it'll take is one word to the pit boss to get them out of your face and on to the sidewalk.
Every casino is littered with bouncers and security officers for just this reason and they get paid to make sure no one bothers you too much.
The real stress comes from having to work day in and day out in an atmosphere that isn't exactly conducive to happiness. The flashing lights and ringing bells can cause a headache or two, not to mention all of the nasty tobacco stank in the casinos and clubs that allow smoking on the floor.
And if you're not into crowds, you probably don't want to work during peak gambling time—especially not on free taco night. That's when things get real messy.