Runups
Yes runups in a piston engined aircraft should be done before the passengers arrive, if possible.
Turbo props are a different story. It takes about five minutes from the time the first prop starts turning to when the wheels first turn. You cannot move till the flags have all gone away. And you can do serious damage to propellers in this time. When we first got the Kingairs we used to carry a broom and sweep the area beneath the props before starting.
Most of the aboriginal communities in central Australia have gravel airstrips, but have a small concrete pad in the parking area for the turboprops(which they used to own) to park on.
You will find yourself most unpopular if you park nyour bugsmasher on this pad when a turboprop is coming.