IUPAC name for branched alkane
Answers to numbered questions:

1.&nbsp; Yes (with the errata applied)
3.&nbsp; Yes, however before the lowest locant set rule (P-45.2.2), maximum number of substituents as prefixes rule (P-45.2.1) is to be used. (See e.g. Alkane nomenclature - choosing the parent chain - maximize or minimize substituents?)
4–5.&nbsp;No, “prop-2-yl” is an incorrect spelling of propan-2-yl (P-29.3.2.2), which is preferred to both isopropyl and 1-methylethyl (P-57.1.1.1).