Blue smoke means your engine is leaking oil inside itself and burning up, you'll have to replace various gaskets and seals, depending on where the leak is.
Yes. You can put a hitch on a Dodge Neon.
No, it will not interchange.
Yes
Yes
A 2001 Dodge Neon uses red, hoat type antifreeze.
Cables connected improperly Dead short to ground in electrical system
yes
No, the years have to match.
Yes there is no difference in the two years 2001 was a carry over from 2001.
NO
It does not contain any Freon.
You can put the 2003 bumper on a 2002 car, but you will also need to replace the headlights with those from an 03-05 Neon and replace the hood with that of an 03-05 car.