They are found out do you take a chance to minimize the risk from that? Or do you ignore a company of elves that might come investigate their friends absence and find that a town is evacuating? Do you take the risk they will act with secrecy in their flight to inform others? Or do you neutralize that risk? The problem with your scenario is you've already come to a conclusion and are only seeing the viewpoint of that conclusion.
His actions are not counter to anything shown on the show as it those actions worked out, right? Again you keep arguing as if the elves are required to never fail.
So you complain that world building is not taking place but then complain when world building takes place just to build the world? You are never satisfied and it is strange how often you contradict your own arguments. Of course the absence of a main character would relinquish a story to a foot note. That is the difference between a main and a non-main character. lol.The entire setting we have right now is contrived and set up for one purpose- introducing Arondir's character and purpose in the story. That's all. If not for this one character, the entire plot would merely be a footnote.