8. "Weddings (which are forbidden during this time" are not comparable to Bris Milah and Pidyon Haben, which are permitted because they are time-dependent. Additionally, you don't really have "Simcha" (joy), for real joy is only in matches (for matrimony) at which we declare "שהשמחה במעונו". Therefore anything related to marriage is considered to be joyous. But that is not the case for circumcision and redeeming of the first born.
9. When a Bris takes place any day from Rosh Chodesh (Av) through Tisha B'Av, the custom is for the mohel, sandak and the father to wear Shabbos clothes. All of the honorees, including the kvatter, do not wear Shabbos clothes. However, women do have the practice to wear Shabbos clothes, because this is their main observance of the mitzvah - their wearing fancier clothes in honor of the Milah.
27. For a circumcision and a redemption of firstborn..., people may eat meat and drink wine if they are participants in the Simcha. [Hosts] need that ahead and extend invitations to people with whom they have no connection, just for the sake of the Bris. One who normally would not be there should not take advantage of the opportunity to eat meat even if it is it legitimately special occasion.
MY TAKE HOME LESSONS:
1. The Simcha at a joy is emotionally subjective. Objectively, Halakha only defines real Simcha as the kind you have at a wedding. Certainly there is a joy at a wedding unlike at any other occasion, with a band and with music and dancing, which you simply don't have at a bris. Also, we note the reality that - albeit for a very short time - the baby experiences pain, and that takes away from the full Simcha we might otherwise experience. Though we skip tachanun on bris days, we don't skip Lamnatzeach, which includes the words יענך ה' ביום צרה, for precisely this reason!
2. Women and men have different ways of celebrating special occasions. Men more actively participate in the mitzvah, while women dress nicer (much nicer) than men tend to!
3. Specifically looking to manufacture reasons to eat meat during the Nine Days is generally frowned upon.