תנא מניין לברכת חתנים בעשרה
From know we that Birkat Chatanim needs ten men?
אי איכא פנים חדשות בריך כולהו ואי לא אפושי שמחה בעלמא הוא
If there is panim Chadashot, it's good enough to provid meals characterized by abundance.
Thus we need two conditions to allow us to make Birkat Chatanim. Ten men, Panim Chadashot.
שקדו חכמים על תקנת בנות ישראל שיהא שמח עמה שלשה ימים,
Chachamim were commited to promote the wellbeing of daugther of Israel, and imposed to rejoice with her.
מברכין לבתולה שבעה
They bless for the virgin seven days.
Stated in SA (EH 64, 1:)
a Sheva Brachos se'udah during every day of the 7 days of rejoicing after a wedding.
. Is that a requirement?
A seudah is a requirement, not for the marriage only, but for the whole week. The chatan needs to eat and drink and enjoy with the kalla, at least one per day. The presence of ten men, of Panim Chadashot depends not only on his will, this is not a requirement. But if the conditions are fulfilled, it seems to be a requirement, each day.
•Does it depends on which community you live in?
•Is there a difference in tradition between Ashkenazim, Sefardim and even between the smaller subgroups within these groups?