this is the main theme from movement 4 written out for lead guitar. this is the same starting point as my although that analysis covered only the part marked A.

A is the main theme,
B is the theme, but the root moves to A. (a safe modulation, which usually doesn’t force the harmony to change)
C is a variation, which starts the same, but ends abruptly, and is played an octave up. (it functions as a outro/transition)
D is a note I added to make the excerpt resolve.
the theme is centered around the tonic, E (except when its A), and moves up to the third, and then down to the fifth.
this can be viewed as implying a i-v progression, or outlining an i chord, with diatonic passing tones. I think both perspectives are correct.
Note; that the unaccompanied melody Implies a modulation in section B, which gives it a kind of meta chord progression (or key progression). That progression is;

e | e | a | e

i | i | iv | i

which is very similar to harmony chord progression the occurs underneath each section, except that the harmony finished its progression in 8 bars (repeating 4 times), and the melody takes 26 bars (and doesn’t repeat).
this kind of self-similar structure is common to many types of music, and works very well.