Naw man if he did tell him, wolf would do something stupid and get hurt. He knows that Wolf would do anything for him. So the only way is to keep him in the dark. Love makes Wolf stupid but for Shin he keeps his head.
Then if wolfgang cant keep his cool as you say, why make him king? But lets not forget that Wolfgang did lead a revolt to overthrow the previous king AND succeded. They succeded, Shin and wolf working together. I'm just saying, Shin is the king's maker, and he's not making any king by keeping Wolf in the dark, or dismissing his proposals and decisions (the glases, yes that was important, the personal guard...). Shin is quite elitist... he doesn't get the common people like wolf does. He's too orthodox at times. That's why they need to work toghether. Anyways, some things of the plot is making me mmmm :/
Also it looks like Shin is doing the dirty work that's underhanded and subterfuge. So that Wolf can keep his hands clean and keep his public persona heroic/wholesome. Besides he doesn't know the size of the enemie constituents. I believe he's doing this to take some of the burden off of Wolf. So he can concentrate on affairs of state and the needs of the people. I mean the stress and worry Shin is taking on, is a big burden off of Wolf's shoulders. Wolf can get along with others and be carefree. Whereas I feel that Shin, because of the last King, lost so much. That he doesn't know how to show and receive love or compassion. I also feel that he has a stigma from the old King from being his favorite of the "children". Shin doesn't have the true respect of the public because of that. I'm happy that he finally has the respect of the royals and nobles, and those that work in the castle.
Dont come at me but I have the feeling that Shin doesn't think that highly of Wolfgang. Doesn't trust him. Because how come you're making plans to protect the king and dont share them with the person himself. Is that hard just to work toghether as a team? Then why did he make him king in the first place?? I don't know, I just get the feeling that Shin sees Wolfgang as a chess piece a little too much.