Most of the time I play guitar lead sounds, or piano. Audiences can relate to my being able to produce those sounds on a keyboard. Most of them are used to seeing guitar players with at least drum and bass tracks.
I will occasionally play a song from youtube if the situation merits, but I make sure to stand up so they know I'm not representing that I'm playing it.
As far as justifying arrangers; I don't feel a need to do that; they have kept me from having to get a "real job" for many years.