Originally Posted by: apoth why do you use this pattern for a scale, and how did you come up by it?". The big question I had, and this is the subject of this post, was: "Why are the strings arranged EADGBE?"
So, my questions for all of you are: what are the flaws in the perfect fourths and major thirds tunings, and what are the perks?

why do you use this pattern for a scale

The answer to that question is simple.
Is about the fingering that allows you to play the notes of that scale without having to stretch your finger more than five frets. Which makes things easier when "sweeping" that scale.

"Why are the strings arranged EADGBE?"

The basic musical scale unit of ancient Greece was the tetrachord meaning literally four strings.The notes of the tetrachord were always tuned to the interval of a diatessaron (fourth)