Well, whether they can take it away themselves or just have a mortal/hearer do it for them wasn't my original point, my original point was accessing the Succor without their permission will get them to try to stop you and would definitely get Gridania to stop you - making an unapproved White Mage highly unlikely. But we're so far away from that point right now.
Personally, it's not defined in lore and I don't let it define who I interact with (There are also plenty of people in my guild who disagree with my assessment of the Elementals themselves), it's just something I think they might be able to do. They may not be able to, which would explain why they have such tight control over who can access the Succor or not, because once they hand it over they can't take it away, and I'm okay with that.
Personally, it's not defined in lore and I don't let it define who I interact with (There are also plenty of people in my guild who disagree with my assessment of the Elementals themselves), it's just something I think they might be able to do. They may not be able to, which would explain why they have such tight control over who can access the Succor or not, because once they hand it over they can't take it away, and I'm okay with that.