My biggest issue with the Finale

The guards are useless!

So a member of the team just tried to assassinate the princess, there should be no reason the rest of the team is allowed to walk around the castle at all. The team should all be placed in jail, some kind of lockdown, or just killed outright. We know Waller called the guard but saying "Whoops my team is about to try to kill your princess because of our mistake" would not make the situation any better. In the best case, the team should have been shipped out of the country immediately. The team being free to walk around the castle minutes after an assassination attempt doesn't make sense.

Ok let's accept the team/waller somehow convinced the guards that Nina was a rouge agent or something like that. Why is there not a platoon of guards following the princess when an assassination attempt happened not even 30 minutes ago? Like in real life, protective services don't just leave their political leader alone for entire days if there is an assassination attempt. There aren't any guards outside or even inside the princess's room, The bride (who they know is armed) is allowed to just walk in a room with the princess alone. At the very least there should be guards around each member of the team.

After this Bride is able to just walk out of the princess's room with no guards checking in after, despite the bride leaving in an angry, rushed fashion and her also assaulting someone on the way out. The team shouldn't be able to just walk out of the castle and not a soul checks the princess's room. Them sneaking out to avoid detection would have been ok but just walking out the door?

This is a major reason why Nina's death isn't settling well with me. Why does the team overcomplicate things with putting someone who isn't skilled in that position when just walking in, blowing the princess's head off, and walking out unscathed worked with no complications, especially during a time when guards are supposed to be extra vigilant? It makes Nina's death feel plotless cause the characters could have just acted rashly and not properly for a military mission and be rewarded for acting illogical. A bit ranty but this plot hole irks me so much