I was just thinking along the same lines before reading the last comment. To avoid direct deposits into temples, make it so elder or priest has to sponsor the estate/temple. The priest wouldn't have to be an elder, but it has to be one of the two- at least somebody with strong ties to the church.
To counter using characters as temporary elders or priests to get temples and then demote or change class, have a mechanism like religions collapsing due to lack of elders/priests/temples. Have it so the church can designate a new caretaker to the estate, so long as the character is not banned from the realm, with maybe 3-5 days/turns?
