Re saying Kiddush on beer - is there a difference between the Kiddush of the night and the Kiddush of the day?
Answer:
In the night, it is better to make kiddush on bread than on beer (as ruled by the Rosh, cited by the Shulchan Aruch 272).
In the day, one must make kiddush on beer, because one eats bread anyway, and kiddush on bread would mean that the kiddush is not discerned (because there is no separate berachah for the kiddush). See Shulchan Aruch Harav 299.