No taboo on anything. Many folk styles use open strings as drones; without retuning, the keys in which open drones can be used are D G A. The fiddle has resonances which give some extra tone quality in these keys.

It's also true that many folk styles play many notes to a bow, and many players hold the fiddle at the elbow, and it's common to hold the bow halfway up the stick.

These are observations not rules of what should be.

Stu