Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

Description:
Master of the spirit world, the spirit shaman follows a different divine tradition from that of the cleric or druid. Her world is filled with powerful, living spirits, some helpful and some malign. By bargaining with these spirits, the spirit shaman gains power over the natural world and mighty divine magic with which to aid her comrades or smite her enemies. Creatures that are considered spirits include fey, elementals, and incorporeal undead such as wraiths and shadows.
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So i was looking at the spirit shaman base class and i was wondering why it is that we can only pick from a list of about 8 nature only deities?

Why can't spirit shamans worship most, if not all gods? Because as it states above spirit shamans should be able to serve all gods since they get their power from spirits not strictly from gods of nature as druids do.

Possibility something that can be fixed or altered?

IIRC:
I think nwn2 bound deity selection to spell list. Druid spell list is bound to druid deities, and since spirit shaman uses the druid spell list, RiP.

Reason it could happen to rangers is because no-one else uses the ranger spell list.

Though, the dev team here has pulled out some miracles in the past, so you never know. I should probably just let one of them comment properly