At the beginning when Chuckie is turning on all the toys in the office, he flies a helicopter and the string is so visible its funny. The helicopter then crashes and you can still see it. In the next shot the man looks at it and there is no string.
Chucky always loses his right hand before he dies. Here's the proof: in Child's Play, Andy's mom shoots it off. In Child's Play 2, Chucky tears it off to escape from a bar. In Child's Play 3, Andy cuts it off with a knife.