So I've been contemplating this for some time and am in agreement with the 'more battles' thing, as I personally suffer from being in realms with less nobles than there are regions. As such, as much as I like the original idea, I would not want to add to that problem.
So I am going to outline then just a few basics for this idea, in its modified form.
1) I want to stick with the Druidism idea, the whole idea of this religion centers around animals, nature and neutrality.
2) Barring that, I think the 'religion' would be best off being comprised of an official religion and possibly a guild.
A) If it is a religion, it can at least be 'religiously' peaceful, IE, tolerant of other religions and not seeking out the destruction of other faiths.
B) With the guild house 'attachment', it could be an order than can 'spread' to other regions that do not carry the faith (that'd sort of tie in with the religious tolerance issue, lords not of the faith could construct guild houses of the 'faith' and not be part of the faith officially, IE, religious tolerance).
C) This would open up the entire structure to a potentially more organized 'economy' and communication structure with various ranks for faithful and non-faithful members.
3) Going back to what I said before about having adventurers take on the role of 'lesser druids' (IE, fighting evil), this would allow priests and the like to take on the role/title of 'Druid' in order to spread the faith and potentially act as neutral mediators when necessary. The guild/religion's primary focus would be fighting 'evil', rather than stepping on the toes of others, but this doesn't mean that the order would be opposed to the idea of declaring various realms as 'evil' in a similar light to the monsters, undead, daimons, etc that plague the lands.
Overall, I am going to keep working on this idea until it seems to be an ideal fit for the game, I think I can make it work but I am sure there is still much to consider. I haven't had a whole lot of time to think about it since my last post (work, work, work...) but this is sort of where I sit with it right now.
I like the idea of involving adventurers because it gives them something to do and potential RP involvement with non-commoners that can lead to the adventurer's player taking an interest in a particular realm and perhaps creating a new character there, or, getting his/her adventurer up to noble status and thus exiting the status of 'lesser' druid.
I also like the idea of involving priests as sort of the middle-high range members of the order, and combining the guild house with the religion means the order can be more flexible in who it has as members as well as survive even if the religion in general flops (sort of how the whole concept of a 'Druid' exists today, yet the pagan faiths surrounding it have waned considerably over time).
Any additional thoughts on the matter?