Here at Mah Rabu, there have been lots of posts where I've said "I'll talk about that in a post of its own", and then never gotten around to it. So now, one by one, I'm going to try to write those posts. If you can think of any Mah Rabu posts that were supposed to have been written and haven't been written yet, say so in the comments.
As promised, this is the post where I list the microscopic differences between the prayers that I say and the prayers printed in the traditional siddur that I use, in order to encourage others to do the same and open up a conversation.
I don't claim that this is entirely self-consistent, and it's certainly subject to change.
The siddur that I use most often on Shabbat is the Koren chumash with the Shabbat (and immediately pre-Shabbat and post-Shabbat) services in the back, so I'll just use that and go in order.
[UPDATE: I should have specified nusach Ashkenaz rather than just assumed that it was the default; Koren comes in both flavors. I apologize for the ethnocentrism. Thanks to JewDot for indirectly bringing this to my attention.]
p.3: In the first blessing of the Amidah, I use the version in all Reform siddurim of the last 15 years:
בא"י א-להינו וא-להי אביתינו ואמותינו, א-להי אברהם, א-להי יצחק, וא-להי יעקב, א-להי שרה, וא-להי רבקה, א-להי לאה, וא-להי רחל, ... וזוכר חסדי אבות ואמהות, ומביא גאולה ... בא"י מגן אברהם ועזרת שרה.
So this version includes both the patriarchs and matriarchs, lists both groups in chronological order, but doesn't put the group as a whole in chronological order (probably to maintain "א-להי אברהם, א-להי יצחק, וא-להי יעקב" as a unit, based on Exodus 3:15), and talks about redemption rather than a (single) redeemer.
Some argue that 1) avoteinu is inclusive to cover both genders, 2) if you say "avoteinu v'imoteinu" here, then you've made it be uninclusive in all other cases, 3) if you say "avoteinu v'imoteinu" here, then you have to do that in all other cases. I respond 1) maybe, but there's no harm in doing it this way here, 2) I don't think this kind of consistency really exists (outside the Gemara's games) where if a word means something in one place then it must mean that in all other places, 3) in hachi nami.
In the second blessing of the Amidah, I also use the version in Reform siddurim, changing מתים to הכל in all four places. God does not revive the dead, but God gives life to everything. Living in the US (with all Ashkenazi lineage, AFAIK) but having lived in Israel and picked up some Eretz-Yisrael minhagim, I'm agnostic about מוריד הטל.
p.5: In the extra blessing that was added to the Amidah, I use the version from Ha-avodah Shebalev, the Israeli Reform siddur:
התועים אליך ישובו, והרשעה כרגע תאבד, והזדון תכניע במהרה וימינו. בא"י שובר רשע ומכניע זדון.
This version focuses on destroying evil, not destroying evildoers.
p.6: For the antepenultimate blessing, I use the version in Gates of Prayer:
רצה ה' א-להינו בעמך ישראל, ותפלתם באהבה תקבל, ותהי לרצון תמיד עבודת ישראל עמך. א-ל קרוב לכל קראיו, פנה אל עבדיך וחננו. שפך רוחך עלינו, ותחזינה עינינו בשובך לציון ברחמים. בא"י המחזיר שכינתו לציון
Also, on this page and anywhere else it says אבותינו, I add ואמותינו.
p.8: Kaddish. I add ועל כל יושבי תבל in each of the last two lines (I don't understand why many people add it only to the last line).
p.9: Aleinu. Like most siddurim until recently, I don't say the line "שהם משתחוים להבל וריק". But I like one thing about that line: the particle "she-", which introduces a subordinate clause, rather than "va-", which introduces an independent clause. Both this line and the next line ("ואנחנו כורעים") are supposed to be part of a subordinate clause, but when the first of those lines is eliminated, then "ואנחנו כורעים" appears to be an independent clause. So I change one letter in the usual text of Aleinu and say "שאנחנו כורעים". I think this version is less problematic. Instead of saying "You have separated us from everyone else. [full stop] We bow down to you...", it says "You have separated us from everyone else in that we bow down to you", and "we" can be defined as broadly or as narrowly as you want.
Kabbalat shabbat: pretty straightforward and uncontroversial.
p.17: I don't say Bameh madlikin. And I'm almost never at services where anyone does.
p. 21 (in Ge'ulah): משה ומרים ובני ישראל
p. 22 (end of Hashkiveinu): הפורש סוכת שלום עלינו ועל כל עמו ישראל ועל כל יושבי תבל ועל ירושלים
Amidah: same issues as above, and for all other Amidahs.
p. 28 (Me'ein sheva): avot v'imahot as usual. I should probably say מגן אבות ואמהות and find a way to squeeze this into the melody. מחיה הכל
Aleinu and kaddish as above.
p. 31 (kiddush for Shabbat day): my family's minhag (German, I think) is to say just Veshameru and then the al kein line.
p. 33 (Yigdal), which, in my cultural context, I am almost infinitely more likely to sing on Friday night than before shacharit: I follow the Reconstructionists. The word משוחנו in the penultimate line becomes גאולתו (with the added bonus of a rhyme within the line), and מתים יחיה א-ל becomes חיים מכלכל א-ל in the last line (grabbing a different piece of the Gevurot in the Amidah).
p. 35 (birkot hashachar): Following all liberal siddurim I'm aware of (and, I hear, some old manuscripts too), I say שעשני בן-חורין and שעשני ישראל. Following Siddur Sim Shalom and Siddur Eit Ratzon, I say שעשני בצלמו.
p.36-45 (other preliminary material, up through Rabbi Ishmael and kaddish derabbanan): I pretty much never have occasion to say this stuff.
Pesukei dezimrah: I don't change what it says in the psalms.
p. 61-63 (Nishmat through the chatimah): אביתינו ואמותינו when appropriate
p. 65 (Yotzeir Or): Right before El Adon, לתחית המתים becomes לחיי עולמים, following one option in Siddur Eit Ratzon.
p. 70 (Ge'ulah): Following Siddur Eit Ratzon,
אמת שאתה הוא ה' א-להינו וא-להי אבותינו ואמותינו
מלכנו מלך אבותינו
גואלנו גואל אמותינו
p. 71 (Ge'ulah): משה ומרים ובני ישראל again
Amidah: mostly same as before. In the intermediate blessing, ערלים changes to ערלי לב, in reference to Deuteronomy 10:16, Deuteronomy 30:6, etc. (similar to changing בבשרנו to בלבנו in birkat hamazon).
p. 82 (Berich Shemei): I don't usually say this. Not for any principled reason.
p. 86-87 (Yekum Purkan): Usually this is my bathroom break, but if I happen to be saying this, I obviously take out ונשיא and ונשיהם. (In Siddur Sim Shalom, they fix it in Hebrew but not in Aramaic. Is this dog-whistle politics? Are they assuming that anyone who understands Aramaic is ok with women being less than full members of the community?)
At this point, my main Shabbat morning minyan says the "prayer for our country". So yeah, I guess I say it without modification for the moment. Let's hope for the best. In the prayer for the state of Israel, I say שתהי ראשית צמיחת גאולתנו, following Soloveitchik.
p. 88 (birkat hachodesh): I follow the minority of siddurim in saying החודש הבא (not הזה), because it makes logical sense. And I like the longer Eretz Yisrael version of יחדשהו.
p. 89 (Av Harachamim): Skip! I'm not into martyrdom or revenge.
Musaf: Yes, I say musaf. I'm not convinced by the usual Reform arguments for taking it out. It goes something like "The musaf prayer is said in place of the additional sacrifice that was offered on Shabbat and holidays in the Temple, and we're not interested in rebuilding the Temple, so we don't say prayers that are based on Temple offerings." To which I respond "Is that so? Then WHAT ABOUT SHACHARIT AND MINCHA?" The whole large-scale structure of Jewish prayer as we know it is modeled after the structure of Temple worship (yes, I'm siding with Rabbi Yehoshua ben Levi on Berachot 26b; what are you going to do about it?), so it seems arbitrary to eliminate musaf while maintaining the rest of the structure.
p. 93 (the middle blessing of musaf): I keep it in the future tense. I understand it metaphorically, and hope for future redemption, rather than fixating on the literal animal offerings of the past.
Shabbat mincha: mostly the same as everything else
p.111 (the middle blessing of mincha): Anyone know a version of this that includes the imahot?
p. 114 (end of the mincha amidah): Yeah, I like the Eretz Yisrael minhag of doing Sim Shalom here on Shabbat (and Shalom Rav on weekdays).
Weekday maariv: mostly the same
p. 137 (Baruch Adonai Le'olam): I don't say this (as in Eretz Yisrael and many other minhagim). How is it ok to add an extra berachah here?
And that's about it. How about you?