Abelleh: (2) most Chasidim, and many others are makpid to wait a full 7 days from the moilad before saying Kiddush Levonoh
(3)Minhag HaGro (i think) not to rely on pas kisnin for kiddush bemokoim seuda, only pas gomur.
Regarding upsherin Rabbi Bimyomin Shlomo Hamburger has an extensive piece about it in one of his seforim on Minhagei Ashkenaz – I dont remember which volume offhand.
And since we are talking about strange (!) minhagim how about not saying Ledovid Hashem Ori at all; not saying Mizmor Shir Chanukas Habayis; sitting down for Mizmor lesoidah (I think the Be’er Heirev mentions this one); sitting for Hallel Hagadol on Shabbos and Yomtov.