Also, after I run out of movement, let me choose my ending facing plz.
Holding ctrl allows you to rotate your character, I believe.
The way I understand it, there is a small area or zone surrounding every character and npc. If you leave that area, it prompts an AoO. Thus, if you are careful not leave the area in your attempt to get behind them, you can avoid the AoO. In other words, I think it is working as intended. Now, whether or not trying to get behind someone should trigger an AoO is another matter.
OP's point is that the game's pathfinding should automatically allow you to run around the enemy without provoking enemy attacks. Since OP can do this manually by taking small steps, the pathfinder should be able to do it too.