Well again, it doesn’t say “once the fire is out” It says “once water is applied”. The goal is to make the environment more tenable as quickly as possible. We’re not as concerned with damage to the property at this point. The main focus is still making things easier for the interior teams by removing heat, smoke, and heated gases. And potentially increase the odds for any survivors. Once we’ve made the environment safe for firefighters, searched for victims, and put the fire out, then we switch to preserving property.

We don’t want to open doors at this point. Rooms within a structure should be closed/isolated. We want heat/smoke/gases to be removed directly from the structure, not fed further into the structure. But yes, opening windows is a valid form of ventilation, we don’t always need to break things. Once the fire is out, interior doors and fans absolutely help.

Ventilation shouldn’t be random, it should be coordinated with the interior attack team(s) so that it occurs closest to where they are working. Yes, improper ventilation can feed a fire and alter its flow path, I don’t think anyone would argue that.