Sharp needles are disposed of in hard, plastic containers to prevent them from sticking anyone. All of the needles that stick Chucky in the dumpster are either loose or poking through plastic bags.
Tiffany, upon first meeting him, suggests to Charles that he go by the nickname Chucky instead. However, the origin of his Chucky name is that it's the name that was assigned to his specific Good Guy doll body, as the gimmick with the dolls is that each one has their own unique name, as shown various times throughout the films with other Good Guys dolls (like in Child's Play 2 (1990) where the Good Guy doll that Chucky destroys is called Tommy).
The character of Nica is repeatedly exposed to the sight of blood without compulsively turning into Chucky.