I'm a traditional-ish

I wrote recently about traditions within Judaism and, unlike earlier experiences, writing has not cleared my mental cache -- instead it has spurred on more questions. Now, I have a site that I go to when I have to ask questions, but this is a bit too extensive for the format of that site so I will just place the whole ball o' wax here in the hopes that someone will read it and explain it all to me. I do, however, recommend the other site if you want to read up and enter the discussion about other topics related to Judaism.

So if you are not conversant in Jewish law and tradition, you can follow along. Sorry if you don't understand all the words and concepts -- I'll explain what I remember to, but I have spent so long not making sense that it is sort of my default and I don't always notice it. If you are a relative expert, chime in but please, please be gentle -- I am still a child in terms of my learning and am soliciting help because I am starting to come to terms with the volume of what I don't know.

I am confused about what exactly, under Jewish law, counts as a minhag. "Minhag" is a Hebrew word which is often translated as "tradition" but it isn't exactly just tradition. The word comes from the concept of "guide on a path" or something like that. In Jewish law, something that is a "minhag" is abided by often, very closely. A community minhag, a family minhag or a geographical minhag is often elevated to the level of ersatz-law and must be followed to that degree. Many well known practices are really the result of minhag which must be followed: the not eating of legumes on Passover is a minhag of Ashkenazic Jews ("Ashkenazic Jews" refers to Jews of European extraction and is not identical with "Minhag Ashkenaz" which is a tradition of people specifically from Germany, as opposed to, for example, minhag Polin for Jews from Poland. Both are Ashkenazic but still differ in some liturgical practices) and is considered pretty firm as a practice. [strangely, the minhag of adopting some prohibitions related to mourning during the Omer period between Passover and Shavu'ot can be altered year-to-year in terms of which days one applies it to, so the notion of a minhag's being fixed sees not to apply.

Many traditions are passed down from father to children and the abrogation of a practice received from a father might even require a religious exemption/voiding of a vow, an actual rite, assuming one has parental permission or some other mitigating factor. This is not stuff to be taken lightly. However, I do not feel comfortable with what exactly counts as a minhag and what doesn't, and I have a bunch of other questions about them, so if you have answers, let me know:

1. Is one bound by a parental minhag if the parent adopted it without any particular reason? [this begs the question of how we adopt a minhag if we have no communal or familial tradition -- if it is ever by simple diffusion and convenience, is it then binding on later generations?]

2. Is a subtle liturgical change (a girsah) tantamount to a minhag? There are many situations where different siddurim (prayer books) even ones which are all, ostensibly, from the same general tradition, have slightly different wording (the absence of a prefatory letter "hei", the shift from "b'fi" to "b'feh", the use of "yitgadel" vs. "yitgadal", "latet" vs. "leeten", "hameichin" vs. "asher heichin") or even more substantial wording changes ("ne'ima kedosha" vs. "ne'ima. Kedusha", "ishei yisrael - ut'filatam" and "bracha hameshuleshet - batorah") which bring up grammatical and meaning differences.

3. If I have my particular liturgy based not on explicit instruction from a parent but because of the habit of having used a specific text, does that make that combination of words my "minhag" or just my practice? Am I not allowed to choose a siddur which would have me say prayers that my father doesn't say because he uses a different siddur or use wording different from his practice?

4. In my Ashkenazic siddur, there are sections that are labeled "minhag Polin" and "minhag Ashkenaz" indicating that liturgical shifts ARE (nominally?) considered "minhag". Is choosing to say one or the other as binding as any other minhag? There are also sections (daily vidui/confession) which are NOT labeled as minhag, but presented as normative practice (as opposed to the Artscroll which says that the Ashkenazic practice is NOT to say daily confession). Mine also includes the phrase "morid hatal" but doesn't tie it to any specific group, just indicating that "some say" it. If I have adopted the siddur, have I adopted all the concomitant liturgical practices? Are they "my minhag" now? Are insertions the same as variations in terms of minhag? Are single word insertions the same as paragraph or full-prayer insertions?

5. Is not having the minhag to do something the same as having the minhag not to do that thing? If someone in my shul adds in "bizchut avraham/yitzchak/ya'akov avinu" during the repetition of the Amidah service and I like that, may I simply start saying that, or does the fact that I have inherited no tradition TO say it the same as having a tradition NOT TO say it? Is it easier to adopt than to drop a minhag?

6. If there was a standard practice in my school, or something done by my rebbe in school which I copied (not because of any research but because it filled the void of [passive] instruction or I was exposed to it from the age of 3 before my father explicitly taught or demonstrated his practice) does that become my minhag? What if it eventually contravenes the tradition of my father?

7. Are practices which are listed in codes of law as "minhag chassidut" -- a practice of piety, such as checking tefillin during the month of Elul, the same (as binding in the future) as another minhag? May I not adopt it if my father hadn't adopted it? Must I do it if he did do it?

8. Are other aspects of behavior considered minhag? Is dress minhag or just a communal practice? What about moving my head in a circle during the saying of the Sh'ma. Some people touch their tefillin at certain points during prayer while others don't. Are those actions minhagim and binding?

Maybe this stuff is obvious to you, but I am at sea, here. Any input and discussion is invited, welcome and appreciated.