(The only mandatory Compline element currently missing in the booklet is antiphon to the psalm. Wouldn't it be worth adding?)

My first version of the Compline booklet did have the antiphon, just as text. It's not historical, so I assumed it wasn't essential - and I couldn't find a traditional chant for it? Do I just have to invent one?

I did use Sibelius for the modern notation parts, and inserted them as graphics.
As for pointing, what's LU, sorry? In your version do you put parentheses around words? That seems to add more complication too? My aim is to keep it looking fairly clean. I'm interested to see other notations.

If you wish to use English, yes, you need to make up a sort of antiphon, but the chant elements come from other sources, in Latin. And why not use Latin?

I would number the doxology if you're going to use numbers that don't correspond to the actual verses, à la the Liber Usualis (I too do this, albeit in Latin).

The lettrine package would be nice for the reading and the collect (I'm thrown off personally by the ordinary paragraph indentation in the reading, which isn't typical for liturgical texts).

Also, you can play with the list feature; enumitemallows for some very cool effects, and I test them with showframe.

Finally, you have a lowercase "y" at the beginning of some verses that may be so in the source, but it's a bit odd in context, at the beginning of a verse…

anyway, as I said, you deserve points for LaTeX.

As to the pointing:

I am not sure that it's clear. One reason for using mode 8 in English (or sometimes the only tones for modes 2 and 5), in addition to the antiphon being in that mode in Latin, is that the accented syllables typically work out to fall on spondees without needing to adjust much. The first verse is good, and it's an example of what I'm trying to illustrate. But sometimes you have two bold syllables followed by either what I consider to be spondees ("darkness" and "refuge", and I'd put the accent on "dark" and "re") or where the two monosyllables can be considered spondees (I would sing "only to look") or dactyls "You will tread). And so on. I do not care for singing monosyllables in a modified way in Latin or in English. That is a legitimate choice. It's just that looking at the pointing, I'm not sure where to move to Re — on second thought, is the second bold syllable where we would have a white note on Do? As a personal preference, I prefer pointing the first verse with chant and going from there, but again, not everyone does, I'm just trying to figure out the system.

Some directors will sing "never ap-proach", but I would not do that myself.

I second Richard's point as well. "buckler and shield" and "without end. Amen." also were not how I would be used to this. But the finals all look fine otherwise.

In the LU or Liber usualis the tone looks a bit like the attached: accents on the bold syllables and italics for both of the syllables at the start of the termination, so "…in the shade of the Almighty." The white noteheads are used only when needed; my parentheses aren't really necessary when the extra notes are given.

Another convention is found in The Plainsong Psalter, which points Ps 91 to tone iv:

He whö dwells in the shelter / of the móst high, *

abides under the shadow / of the Almíghty.

I imagine tone viii would then look like:

He who dwells in the shelter of the / móst high, *

abides under the shadow of / the Almíghty.