You got a model? You could be talking about anything from a W900L to a T300. They're not all the same. 3 lbs., 12 ounces is typical for the 'full size' daycabs (T800, W900, etc).
2
No, unless the a/c has been converted to r134a
R134a
R134a
R134a
R134a
Go to autozone and they will show you...
R134a Refrigerant
R134a, just like any other vehicle for that model year.
Not without modification.
R134a
it uses R134a refrigerant