The Doopie Bros: Captain America Civil War Review

Good review. The first thing you mentioned is Cap's motivation for not signing the Accords. Here is my take on his motivations.
Ross tells them that the U.N. will decide which missions the Avengers will be needed on, and which ones they will not be needed. That point takes me back to "Captain America: The First Avenger". The first job Cap had after taking the super soldier serum was working for the Government, and they had him selling Bonds.....or as Colonel Phillips called him "a chorus girl". Better then being a lab rat, but no where near the job a super soldier should be doing. A good example of why the Government shouldn't decide which job the Avengers should do.
Then in Europe Cap finds out about the soldiers the Skull has and instead of helping Cap free them, Col. Phillips says they will be rescued once the war is won. Cap goes against his commander and rescues 400 soldiers, afterwards, the Col. gives Cap more freedom to fight Hydra the way he sees fit. This is a good example on why the Government shouldn't decide which jobs the Avengers shouldn't go on.
Of course you also have the Winter Soldier movie where Hydra has all but taken over S.H.E.I.L.D so naturally Cap's not too excited about having the Government make his decisions for him.
I hope that explains Cap's motivations a little more.