Oh man that's lovely. This really fits the setting's work, too.
Then just assume anything is plausible. I'm intentionally not putting limitations on the exercise--to not curtail creativity, to not provide a wall of text, and because no limitations actually makes sense with the setting I'm making.
They believe in Chirality, that all significant things come in at least two versions, which are fundamentally different. This is most noticeable in their maxim that "Left is Lucky, Right is Regretable." They will prefer the leftmost of a pair, to turn left rather than right, to use their left hands as their primary hands (most of them are naturally right-handed, but view this as a thing to be overcome), and so on. This worldview can be applied to almost anything, and elevates a distinction that is unimportant to most beings to a guiding principle of the universe. They worship a commonplace god, but in a left-handed version.
Or "This reality is but an imperfect reflection of a perfect one. We can change that ..."
That seems to be going beyond what you specified for their eccentricity. It also introduces the familiar clichés of mirror-universes, which I reckon are well worth avoiding.
That works.
1 would be good if the campaign wasn't about discovering actual druidic magic and nature spirits that are contained in one part of the world. The hippy druidism is a bit too coincidental (sort of like the collision of the real world crystal psychic chakra types winding up visiting the place with aggressive psionics).
