Allow Shamans to Own Religious Buildings
The title pretty much says it all.
Shamans should be able to purchase churches, or properties within Druid Groves. Shamans are considered "full" divine casters. Accordingly, there is no substantive difference I can think of that would suggest they shouldn't be able to own religious properties.
I think the case for owning Druidic Quarters (such as in the Zurkwood Grove) is pretty self-evident.
However, I think there is also a strong case for Shamans to be able to own temples / "church structures" within cities. A shaman is every bit as capable of leading a congregation / cult / religious sect as any other divine caster. Shamans acquire their divine powers by strengthening their understanding of / relationship with their deity (or in some cases, spirits).
Meanwhile, Favored Souls are allowed to own churches - but a Favored Soul is not required to have any sort of knowledge of their deity - per the Wiki, some Favored Souls aren't even willing participants in the divine favor they received.
So it seems odd that Favored Souls, a class that doesn't necessitate any sort of divine knowledge, doctrine, dogma, etc., can somehow own a church, while a Shaman, who actually chooses to study and hone their religious beliefs, is unable to lead a congregation in a religious building.
Similarly, as far as I know, characters that aren't even "full clerics" can own temples / religious structures. It seems odd that a character with a cleric dip can run a church, but an Epic Shaman cannot.
While it is true that not all Shamans follow deities - and therefore might not be a good fit for running a church building - this is no different than a Favored Soul who is involuntarily chosen by a God - yet Favored Souls still have the opportunity.
Basically, there's no good reason to mechanically restrict Shamans from owning churches/religious buildings. If a Shaman is RPing poorly with regard to leading a church, then it can be settled like any other instance of poor RP / quarter management - but it shouldn't be used as a reason to prevent them from ever having the opportunity to try.
Lastly, I think there could be many positive developments from allowing Shamans to own temples. They could form cults, or other types of "atypical" religious groups, that would add new flavor and RP possibilities to the community.