I don't think Durkon's order counts as a proxy father. The High Priest of Thor only gets rid of him for what he thinks to be a very good reason. Besides, if I don't consider a job to be a proxy father, even if said job is a religious calling.
Kubota was a right royal thingummywhatsit, Therkla was a minion, just one he happened to be training. She was fond of him, but I don't think he ever had any real affection for her.
And I think you're being unfair to Shojo really, both his "adopted children" are well and truly adults. They're supposed to be taking care of themselves and since he himself had a very different philosophy on the world than they did I'm not surprised he felt it reasonable to deceive them. It's a "one adult to another" thing, not a "parent lying to children" thing. I've found that once you get to a certain age, any reasonable adult treats you as a fellow adult, even if you're a couple of generations below them.