Something I always wondered about...
with 1st and 2nd edition druids in particular,
how do they handle themselves on the planes, especialy in their "keepers of the balance" roles
it must be pretty hard, to do so when good or evil IS the very nature of the place your in...
Well, most I would imagine simply play the role of planar guardian. Planewalking druids would be on an unusual quest *e.g. Dead Gods* to make sure the balance doesn't shift or whatever. Obviously, it's easier to imagine druids in the Beastlands, Arborea, Outlands, or on the Elemental/Paraelemental/Quasielemental planes than it is to picture them in Celestia, Mechanus, Elysium, or most of the lower planes *excepting a few Abyssal Layers*
As far as 3x, many would likely belong to a Gatewarden-like group (I'm actually working on a sect called the Purifiers who fill this niche) whose role is to keep rifts to the Far Realm from opening, thrwarting aberrant and Far-Realm powers, and exterminating non-indigenous aberrations. (in addition to this, they are a sect of nativists who allow some leniency for interplanar commerce)
Druids could also become Doomguard (despite what 2E may have claimed otherwise). Such druids would merely believe that they are maintaining the balance towards entropy as fated.
Likewise, their lesser-known and hidden (due to Doomguard persecution) sect would also have druids with the opposing viewpoint. This sect, which I'm also working on, calls itself "Creation's Sentinels". They believe that the Multiverse is still in its birth pangs, and see everything around them as proof of this. One of the overlying themes in their philosophy is the "Chain of Existence", in which matter and energy take on different forms. For instance, when a mortal dies, it goes on to become a petitioner, eventually merging with a power or with the plane itself. Their essence will then either become a permanent component of the deity's, or it will be used to create something-- likewise, part the scattered essence across the planes could eventually result in the spontaneous birth of an outsider or elemental. Processed petitioners become fiends. The Creation's Sentinels view these scenarios specifically as "transcending to a higher/greater/more perfect form". They also aknowledge that most fiends won't achieve anything better than bottom-tier or even larva, but they do not view the deaths of these creatures as entropic or final-- the slain petitioner simply becomes something else.
Druid hierophants in 1 and 2E are well known for travelling to the Elemental planes, so of course druid planewalkers would be seen there. Most would likely travel to the planes for religious reasons (seeing it as an initiation right or a chance for enlightenment)