Theoretically this is true, but to use Mikoshi (separate V from johnny) without Araska's help, you have to use Alt's version of the soul killer (So destroy Mikoshi).I see your point, but it seems Takemura in this moment wants revenge on Yorinobu using V as witness on the murder, as I said before with the ''strings'' you already fufill this role on the Arasaka Meeting, the point is after that it is stated Yorinobu's betrayal already so instead of going face him you just go to Mikoshi instead... I'm just saying that you are ''locked'' to do this things, you cannot diverge like ''I plan to only help here but I will go under their nose on Mikoshi since the security will focus on Yorinobu leaving Mikoshi open!''
Hanako knowing her father in Mikoshi, I doubt she appreciates it.
Goro being loyal to Hanako, Arasaka and he is soldier above all (since childhood), couldn't let this go
To be seen in the dialogs with Oda on the docks. if Goro had been ordered to cut off the head of Oda (his only friend), he would have done so without hesitation.