2. Supporting characters are important and they need to take center stage sometimes; not for long, but sometimes they really do need to spend some time in the dryer, or in the supply closet with an unfortunate, badge-wearing mustache, or in the bubble bath of their mythological fiance's new wife. Hey, your setting, your rodeo.
4. You do not have to follow the crowd, or join the group that seems most likely for you. (Unless you are a rot-mouth, meth-head, "born-again" hate mongerer. Yeah, there's probably only one crowd for you in that case.) If you're new, but wish you could sit with the old ladies (and word to the wise: they have the least to lose and might be the biggest risk takers of all), finagle a contraband cup of yogurt and go make a peace offering. They just might share all their survival secrets with you. Or maybe they'll shank you in the hallway. Go with your gut.
5. If you're going to go all "Miss Rosa on Vee at the end of Season 2" with a character, the reader cannot still possess the ability to manufacture empathy for that character. That character must be clearly unredeemable so the reader will cheer for that act which they would've never before believed they could cheer. Watch for my QVC video series: How To Turn Your Readers Into Complete Savages in 10 Easy Steps! I'm kidding, of course. (It takes 11 steps.)