Why Engine driven generators produce carbon monoxide, an odorless, colorless gas that can be lethal indoors or in a partially enclosed space, so the unit must run outdoors or in a space with good airflow and exhaust directed away from occupied areas. Proper ventilation also carries away engine heat. Safe generator practice is ventilation, correct grounding/bonding, and keeping fuel stored well away from the hot running engine.
Watch out Insulating the generator from ground is backwards: the frame and neutral bonding must follow electrical code so fault current has a safe path. Storing fuel next to the generator puts gasoline vapors beside a hot exhaust and ignition sources, a fire risk, so 'all these choices' cannot be right.
Generators: fresh air yes, fuel nearby no, floating ground no. CO kills quietly.