1.Signing a form is little more than a formality.
I know the sentence can be changeable like the following below.
2.Signing a form is only a formality.
But can I change the first sentence into others like the followings below, and Is the meaning also all the same?(with number 3,4)
3.Signing a form isn’t much more than a formality.
4.Signing a form isn’t much more than signing a form is a formality.
Lastly, I want to know the part of speech of the word “more” in all sentences above.
5.Signing a form isn't any more than signing a form is a formality.
what difference exists from 1,2,3 and 4 sentences compared with 5 sentence?