Question 1 could be wrong see below video for more detail. It is ch.13 use minimum equation as question wants
Question 2 The most appropriate occupancy classification is Group R-4 (Residential). Under the International Building Code (IBC), R-4 includes residential care/assisted living facilities that house more than 6 but not more than 16 individuals (excluding staff) on a 24-hour basis who receive custodial care.
SBCC WA (.gov) +3