I have non-Jewish guests fairly often (board games are a good way to spend Shabbat afternoon...). Here are some things I do:
Wine: just use mevushal. Why risk either offense or waste? Your human guests are way more important than having the nicest possible wine.
I use a "night light" in each bathroom rather than leaving the regular lights on. It's way ...
The source is a beraita quoted in Sanhedrin 23a:
תניא נמי הכי כך היו נקיי הדעת שבירושלים עושין לא היו חותמין על השטר אלא א"כ יודעין מי חותם עמהן ולא היו יושבין בדין אלא א"כ יודעין מי יושב עמהן ולא היו נכנסין בסעודה אלא אם כן יודעין מי מיסב עמהן:
That is also taught: This is what the scrupulous people of Jerusalem would do: They would not sign a ...
The sefer Pidyon HaBen KeHilchaso 8:37 brings two customs. One is as you described.
The custom of starting the meal first and then performing the pidyon haben is brought by the Maharil, Shu"t Mahari Bruna § 121, Be'er HaGoleh 305:10, Migdal Oz 9:5, and Chochmas Adam 150:7, amongst others.
The Mahari Bruna gives the following reason for the custom: If the ...
As you noted in the question, the accepted halacha is that one requires bread at the first two meals (Shulchan Aruch 274:4). At the third meal, one needs to eat bread as well; however, there are opinions that one fulfills his obligation with mezonot items (or even meat and fish, or possibly even fruit) (Shulchan Aruch 291:5).
Now, the opinion that allows ...
JoelK gave the source specifically mentioning the נקיי הדעת. But as the OP asked for sources, it's worth noting the gemara in brachos 43b which adds a reason to avoid eating with "unfit people":
תָּנוּ רַבָּנַן: שִׁשָּׁה דְּבָרִים גְּנַאי לוֹ לְתַלְמִיד חָכָם...וְאַל יָסֵב בַּחֲבוּרָה שֶׁל עַמֵּי הָאָרֶץ: מַאי טַעְמָא? — דִּילְמָא אָתֵי ...
Some people bring small foods to shul on the day of the yahrtzeit for people to eat and make brachos for an Aliyah for the soul.
It could be that the reason for having a meal is for the same reason.
You could also read this.
Sefer Yismach Lev Volume 4 / Page 92 brings from Tosfos Moed Kattan 8b - Mipnei Bitul Pirya V'Rivya that one may make a Bris on Chol HaMoed as it is not considered a Simcha as there is pain for the circumcised child.
He says that Tosfos finishes and says that there is no issue of mixing Simchas only by weddings.
This publication is relevant to the conversation:
Summary: One should not recite any blessing at all on cakes served at the end of the meal. If the cake, however, contains all three conditions in that its dough is sweet, it is crunchy, and it is filled (like Ma’mool and Baklava), only if the ...