why did they have to kill Chalky white

Live by the sword, die by the sword.

He was always on a destructive path, I don't think there was any other ending for him really.

I like the fact that they killed lead characters sometimes at random times in the season, it gave the show a more dangerous feeling where anything could happen to anyone.

He realized his activities put his daughter (Maybelle) in the line of fire, and that if he wanted the woman he loved (Daughter Maitland) and his daughter - their child - to be safe and free, he would have to lay his life down. He wasn't able to live any other way, and it would have continued to put his family in danger. So he took the noble path, because despite all his flaws, he was a noble man.

Welcome to prime time bitch