OK I have taken a look at this, and while the existing options are not great, this is not a compelling improvement, and I wouldn’t be able to recommend these to anyone asking. The formatting needs a ton of work. It’s fine to have quirks (I never capitalize pronouns mid-sentence even those referring to the Persons of the Trinity, for example.)

“The” is rarely proper; in this case, it should always be lowercase. It is also not necessary on the cover page.

I don’t understand not giving the propers in Latin while giving the incipit, which the congregation never needs. Omitting the doxology is also atypical.

The shifting of the chant alignment to fit the translation is poorly done. Also, in the Gloria, you have no idea when the priest sits anywhere else and with any other celebrant. The Sanctus alignment is probably the best use of the Mass & Vespers formatting; otherwise, it’s better to do like at the Agnus where the translation simply follow.

The indentation shifts unpredictably, as if you meant to use drop caps in the collect but decided against it. The same reoccurs elsewhere such as in the nuptial blessing. This is also true of the dialogues. You don’t need space if you insist on bold instead of the slashed V & R, but those are the standard characters. We are reinventing the wheel here. Also, the Maltese cross is the standard character for the sign of the cross, and the dagger has another meaning in liturgical typesetting. I would simply replace every example of the latter with the former. (There are a few exceptions where one is making the sign of the cross on the lips or the heart but generally one uses the Maltese cross for making the sign of the cross over oneself or an item.)

The spacing of the quotation in the epistle is non-standard. Just put it all in one long paragraph. Ditto for the Gospel. Also, the indentation switching from standard to the hanging indent for the two kind of readings is jarring.

I would not use the ICEL translation especially as you use an older translation for the other parts. (The you-thou usage is jarring.) But if you are going to do so, a copyright statement is not optional, and I am not even sure that you can use it this way anyway (for a one-time booklet, yes; they might be OK with a Latin-English NO booklet, but you have to ask).

“Laus tibi Christe” is not said at a sung Mass anyway, and it’s unclear what the words below it mean if you don’t already know.

The nuptial preface is merely an option. I certainly wouldn’t assume that it would be used…

I do booklets on a semiregular basis. Also, the bottom line for me is that anything silent should be in an appendix with a page reference where it occurs linearly in the Mass, and only out-loud material should be present in the body. People don’t care that much, and if they do, they have a missal or device.

Well, that’s another can of worms. New Solesmes (and everyone but Solesmes back in the day) uses the more classical c-t, but -ct has a long history too.

The problem is that the lines of chant start in different places on the same page…that’s hard to follow.