Wach nacht, Bris milah, and Wimpel minhogim

Please see Minhogei Bris Milloh at this link .
At the night before the Bris a Se'udoh is made, and in the Se'udoh Divrei Torah are said, or that there is a communal learning. Some people stay up all night, but that isn't common.
The people attending the Se'udoh say Shema.

Regarding the Wimpel - see Shorshei Minhag Ashkenaz part 2 .

Women definitely attend the Bris Milloh (in the women section). A woman (called the Sandekes) brings the baby to the men's section.
The mother of the baby wouldn't come to the Bris in the past, but nowadays when people go by car and there are elevators in shul (so there isn't any physical effort in coming), the mother usually comes.
In general the mother wouldn't leave the house until a month after giving birth, when she would come to Shul on Shabbos to hear her husband making a Brocho on the Torah (which comes instead of Hagomel), as seen in length at Shorshei Minhag Ashkenaz part 1 .

Michael FRBSH

MBucher wrote: I would also like to ask if the Yekke way is to have a shalom zachar on the first Friday night after the birth, or only a vach nacht the night before the bris?

It is done, (but it is called a "Zochor", as it was called in all of Europe until the 19th century, and not Sholom Zochor).

MBucher wrote: I would be interested to know what are the traditional food items and prayers for this/these event(s).

Cakes and fruits and other desserts (מיני מגדנות).

MBucher wrote: Is there a kiddush for the bris milah on the shabbes following it, or simply a small meal on the day of the bris?

There is no Kiddush on the Shabbos after the Bris, but two days after the Bris, friends of the family come to the mother's house, wash the baby and make a little party, called Shlishi Lamilloh.

MBucher wrote: What would be traditional to serve? milchig or flieshig? any special item?

Fleishig was served in the Bris meal. Just before the Holocaust we find some mentioning of a milchig meal (in Holland for example).

MBucher wrote: Where could I check the sefer your mentioned in your post, to have more infos on the wimpel?

The Hebrew volumes are out of print, and will be reprinted when the funding will be found. The English summary book can be purchased through Feldheim .

MBucher wrote: I would need to know, IYH, what exactly must be written on it and who exactly can decorate it (should the professional be frum, can be child be ben his father AND his mother, are some things not to be drawn/embroidered on such a holy thing, etc).

It could be done by anyone, although it is best if it could be done by the mother or by relatives. But the most important thing is that it comes out nice.

Michael FRBSH