what would signing below the line signify?

It would prove that you can not follow simple instructions. Period.

and other are allowed to instruct and order me to do things on what basis?

Pun Op? Signature, sign, signify. Is the same word in different tense. Answer "lies" therein.

There on

There under.

Or THERE THROUGH.

Sign on,

Sign under, co sign, under write. Underwriting...

Sign through, mark through. Mark out. No deal.

What if all you signed was one letter?

Sign on. It's a deal.
Sign under. Security for the deal.
Sign through. No deal

One letter is still a mark. Look up the etymology of signature, sign, signify.

thanks i knew there was something to my madness

Word s have meaning. If they didn't we could not use them to communicate. The problem is that meaning must be agreed upon. The problem is that the words used to agree upon things must be agreed upon... Ad nauseam.

This is why legal process uses archetype as much as possible.

Everyone intuits that a signature that has been crossed through is null. A signature under something/one else bears witness. A mark on is the real "deal"

It seems forms always say sign in blue or black. teachers use red for corrections and there are claims that purple means royalty. i notice that when things are stamped paid it is usually in red
does the color of ink have a significance?

Does a X or some type symbol next to the signature have any special meaning?

Lol I don't have time to get into all you questions but will address the black and blue.

In the days before coloured copies blue was the preferred choice for signing This was to be able to tell the difference between the original and a black and white copy. Nowadays it is a moot point though many hold to the tradition or habit.

I got lost, like, halfway through this thread.