I have a theory for the arc that three:
As I said: I think a breakup will take place between Buggy and Shanks. I don’t know yet if Shanks is facing his denial, otherwise I think it might be related to the gang that chased Buggy like the devil. Garling could send them in pursuit of the insects that are around Shamrock and Shanks. Seeing the opportunity, he decides to tackle the sensitive point of Shanks and Shamrock. Since you mentioned it as a link (Buggy), again the two twins might as well shoot him first.
I also have the theory that Shamrock will not shut his mouth as Shanks asked him to do. And that Shanks, faced with reality, eventually rejects his brother, who will return to Garling’s arm. Even if I think that Shanks doesn’t want that, but the twins' feelings are such disasters... I had said it, Shanks is as bad with his feelings as Shamrock.
I also have a Mihawk point of view could be a support to Shamrock. Maybe take it at his place, or at his place and Crocodile.
At first I thought that Doflamingo and Corazon could help knowing the gang! Who attacked Buggy, but I don’t know. Doflamingo makes eyes at Crocodile, he could surely help.
I also have the fact that Shamrock, Buggy, and Shanks can be separated and meet at the University. But that there would be conflicts between them three. And that now more mature and mature. They put the card on the table. And decides to speak like real men.
I have so many theories that my head hurts 😭💚
I love your point of view where you send Mihawk is like their safe Haven hehe:3
We will see more of whats going on on Crossguild HQ in this modern au for sure.
And the university talk, they definitely will have to talk about it soon