The melody is very nice, and I can't think of any ways to improve it. I only found a few minor orthographical and calligraphical issues:
On page 2 in line 3, there should be on oligon placed beneath the two notes for the syllable "tho-" because the kentemata are followed by a descending note.
In the same line, there should be a vareia right after the martyria.
On page 2, line 5, the psefiston beneath the oligon for the syllable "faith-" should be removed because only one descending note is immediately following.
One minor thing I noticed is that you drew the "kappa" in the martyria on line two like an "x". Although it is true that many printed books of Byzantine music draw that kappa like an "x", I think it would be preferable to draw it like a lower-case English "k" but without the tall line sticking up.
Another minor calligraphical issue is that you might consider slanting your vareias a little more or making the tail at the bottom curve out more to the right, because the first vareia on page 1 looks almost exactly like the vertical lines you use to mark the rhythm. I understand, though, that this is just a rough draft that you probably intended to type up neatly before distributing it to other people.