because the manga is following the light novel.  and it just so happen that the anime went ahead since there is already an existing media for its episodes

uhh its already been established that his shadow magic can heal him... its not plot armor when its an established system.

And its not surprising that he also that he has a cr** load of mana because his shadow ate the whole raid. 

jokes aside.

He is the escort of the archbishop. Typical kings meetings in numerous stories have their aide outside the room while the guests are inside the room. 

Him being atuned to even the slightest noise of goblins him hearing discussions about a goblin by the next room is not exactly hard. 

and even if he is not outside the meeting area... the maid has been running towards the meeting area screaming goblins kidnapping the ... i highly doubt the elf or goblin slayer did not hear the commotion

plus didnt you guys watch the da** anime? thats like season 2 episode 10

you forgot that the main reason hancock suddenly liked luffy is because he ignored hancock and treated her normal instead of a horndog right? She didnt fall inlove because he saved her sisters from being exposed, she didnt fall in love because she released conqueror;s haki, She didnt fall inlove because he did heroic feats

He is not a horndog and interacted with Hancock just like how he handled other ladies.