What are the halakhic requirements for Shulchan Aruch OC 590, Seif 1?

Does the Shulchan Aruch's phrasing 'Shabbat hi mi-liz'ok u-refu'ah kerovah lavo' make sense in the context of comforting mourners, where the deceased is already dead?

Circumcision Timing and Preparation

Does the Rambam's understanding of the inferior partition restriction differ from the Shulchan Aruch, and if so, what is his opinion?

Lechi and Korah for Alleyways

What is the Rambam's position on when 'zakheh li' to a baker/shopkeeper is valid vs. invalid, and does it differ from the Shulchan Aruch?

Eruv Using a Dwelling

Does the Aruch HaShulchan accept the Rambam's ruling, or does he follow the majority of Rishonim against the Rambam?

Eruv Techumin Using an Agent

Does the Shulchan Aruch's ruling about a 'window' (chalon) to the back apply equally to a full door (petach), and is the reverse also authoritative — that a full door is required and a window is insufficient?

Conditional Eruv Techumin

According to the Rambam's formulation, is the prohibition in a mixed mavoy (Seif 2) more lenient or more stringent than the ruling in Seif 1 (as understood by Rashi/Tur), and are the two seifim in Shulchan Aruch consistent with each other?

Eruv Techumin from the Road