Yes

Yes

The general custom is to do all whe windings on the arm, then put on the head Tefillin, then complete the windings on the hand and forefinger. There are some who only wrap one or two windings on the arm and then put on the head Tefillin and then complete the arm windings.

Technically, that is the proper practice, and the Vilna Gaon urged it to be adopted by all. However, the usual custom is not to do this, as few people could maintain the proper respect for the Tefillin all day.

If there is a doubt if a letter has its proper shape or not we ask a child. In some cases this renders the Tefillin kosher as is, in other cases this makes a situation repairable (despite the usual consideration of K'sidran-that they be written in order.) Under normal circumstances, and according to most authorities, this is not considered less mehudar. An exception would be when a particular problem is considered possul by most authorities, but a minority opinion rules that it is kosher if recognized by a child, this would be considered B'diavad (Kosher ex=post facto) and would be sold accordingly.

Unfortunately, there are still many problems in this field. Either consult an authority, or buy from a manufacturer who can produce for you recommendations of accepted authorities.

Loose would still be kosher. However, if they are so loose that the stitching has lost its square shape, this would be possul.

A hole in the k'tzitza (the part holding the parshiyot) as well as in the lower titura (base) opposite the opening for the parshiyot, is considered possul by most authorities. A hole in the titura (base) not opposite the opening (where there are stitching holes anyway) would still be kosher, provided they do not adversely affect the squareness.

Yes. It is in fact used in several stages of the work.

All machines we use only work with continual manual action. For instance, an electric drill could be used, but is on a special switch so that it can only work as long as the person is applying pressure. Unlike machine matzot or machine tzitzit, no part of the manufacture occurs automatically. Rabbi Ben Zion Wosner,while visiting our plant was asked this question and responded "Anyone who says this is not Avodas Yad (hand made) doesn't know what he's talking about."

(Approx. every 3 and a half years).

Technically, Tefillin in constant use which have not been exposed to high heat or water need never be checked. However, it is recommended to have them checked from time to time.

You must leave mezzuzot. If non-Jews are moving in then you don't. Non religious Jews are still Jews and you must leave mezzuzot. You can put up less mehudar (but Kosher!) mezzuzot. If the new tenants are religious and have mehudar mezzuzot, you could ask them to let you put them up before you leave.

You must leave mezzuzot, but you can switch them to simple cases.

Not is the squareness is unaffected.

Yes.

Many Rabbis would say according to the custom of your anscestors. I would say that it would depend on your general bent. Is you usually go by the Mishnah B'rura, you should have Beit Yosef (which is the only one dealt with in the Mishnah B'rura). If you have a Hassidic bent, get Ari.

Price is no assurance. Buy from a reputable dealer.

According to the Rambam, a non Jew may perform any Mitzva (other than Shabbat observance) and will be rewarded. There are those who disagree. However, since in your case it is for the purpose of preparation for conversion, I would say that it is clearly permissible. (Good luck!)

That the four parshiyot (verses) (not only the four compartments of the Shel Rosh) represent the four letters of HaShem's Name is found in the Zohar. The Zohar also explains the two practices (that we call Rashi's and Rabbeinu Tam's) as representing two different permutations of the Divine Name.

The poskim (rabbinic legal codifiers) establish their legal decisions on many factors of which one's family custom is one consideration. Most Ashkenazi Jews today follow the decisions of the Chafetz Chaim (Rabbi Israel Meir Kagan) as recorded in the Mishna Brura about one hundred years ago. The knot of the head Tefillin is supposed to form a dalet, which together with the shin on the head Tefillin and the yud formed by the knot of the hand Tefillin spells one of the names of G-d (Sha-dai). As the Chafetz Chaim prefers the dalet shape to the square, which is actually a double dalet, this is today the prevailing custom, which most rabbis would consider to override family custom. However, the double dalet is kosher and remains the custom of many communities.

The shape and size of Tefillin are not mentioned in the Torah itself, but are part of the Talmudic oral tradition. The shape of the Tefillin is set down in the tractate Menachot page 38. It is stated there which biblical portions are written in the Tefillin, Their order, and the requirement that they be square. The early commentators and codifiers interpret the Talmud as requiring squareness in three places, viz. The base (Titura) the case holding the scrolls(Ketsitsa), and the stitching of the base. In Maimonides' Code the structures are described in detail. The requirement of squareness is found in the Code of Jewish Law (Shulchan Aruch Orach Chaim 32:39). What degree of imperfection in squareness would render the Tefillin invalid is still a topic of debate between authorities. As to the size, there is no Talmudic ruling other than the statement that there is room on the head and arm for two pair of Tefillin. Some authorities deduced from this that the Tefillin must be two fingerbreadths (Shimusha Rabba) but this view was not generally accepted. The Shulchan Aruch rules that there is no minimum reqirement as to size (O. Ch. 32:41). We hope this answers your question to your satisfaction.

All the customs are kosher. If you generally follow the Mishna B'rura, do Ashkenaz. If you generally follow Chassidic ways, do S'fard. It is best to pick one and be consistent.

We have discussed this issue with major Poskim who permitted it. It is similar to the issue of non-kosher fish oils once used in tefillin paint (Kesset HaSofer 23:2). Since the blackening agent is kosher, and the fish oil is there for non-halachically required reasons (to make the paint smoother and the straps softer) its' kashrut is not essential. Similarly, nearly all Tefillin paint contains shellac, an insect derivative. There are those opposed, but most Poskim permit it as long as the blackening agent is Kosher. The black color in all markers is synthetic. Some do have a glycerin component which would be permissible for the above reason.

Tefillin are alluded to in four places in the Torah with variations upon "they shall be for a sign upon thy hand and frontelets between thy eyes" The details are recorded in the Talmud in tractate Menachot, and discussed in great detail in the later codifiers. Many Rabbis see a reference to Tefillin in the book of Samuel, when proof is brought of the death of King Saul in the form of "his bracelet and his diadem."

According to the Rambam, Tefillin may only be worn during the daylight hours by Torah law. According to most other authorities, they could technically be worn at night, but the sages decreed against it, lest one sleep with them on. Rabbi Moshe Feinstein permitted one who had to go to work early, if it would not be possible to put them on later (they may be worn until sundown) to put them on before dawn without reciting the blessing. Note, however, that 5 A.M. is usually after dawn most of the year in most places. You needn't wait for sunrise, dawn is sufficient.

Thank you for your question. In Talmudic sources the blackness of the Tefillin is indeed ascribed to "a law given to Moses on Sinai" with no further explanation. Later sources (middle ages) state that the blackness represents the unchanging nature of G-d, as black is the most unchanging color. Hassidic sources connect the blackness with the mystical concept of Tzimtzum, the contraction of the Divine Light (represented by the scrolls in the Tefillin) so that it may be absorbed by us.

Firstly I would like to explain two things to you.

1. The meaning of Nusach and the way in which we use it.
2. The difference between Rebenu Tam and Rashi

1) When we ask what is your Nusach or Minhag we are asking for the custom of your fathers. There are suttle differences bettween the three main customs. There are more then three customs but Safardi, Ashkanazi and Ari Zal are the most popular.

Safardi	Ashkanazi	Ari Zal

You can see clearly the differences with the letter Shin. This is also a way to identify the Nusach of the Tefillin without looking at Parchment. All Tefillin have two Shins on them. The type of Shin will show you the nusach of the Tefillin.
2) All Tefillin have in them 4 chapters of the Torah.

1. Kadesh
2. Vai -Yakev
3. Shama
4. Vai - Yahe im shamoa

It doesn't matter if it is Rebenu Tam or Rashi they will have these 4 chapters. Now the difference between Rashi and Rebnu Tam is the order. Rashi is like the order above. Rebenu Tam (The grandson of Rashi) switches the order of the last two ( c. and d. )
Now to answer your question:
It doesn't matter what Nusach you are it can be either Safardi, Ashkanazi or Ari Zal, the Sofer (scribe) will write the parshiot (parchment) in the order that you want ie. in the order of either Rashi or Rebnu Tam. The laws of Tefillin say that the parshiot have to be written in the order that you put them in the Tefillin ( you can't just write them in one order and put them in the Tefillin in a different order).
FYI. We only bless on Rashi Tefillin. Wearing Rebnu Tam is like for extra...